--- /dev/null
+C RCS $Id: gnuplot.doc,v 1.387.2.51 2009/05/18 02:47:35 sfeam Exp $
+C
+C Copyright (C) 1986 - 1993, 1998, 1999, 2000, 2001, 2004 Thomas Williams, Colin Kelley et al.
+C
+^ <h2> An Interactive Plotting Program </h2><p>
+^ <h2> Thomas Williams & Colin Kelley</h2><p>
+^ <h2> Version 4.2 organized by Hans-Bernhard Broeker and others</h2><p>
+^ <h2>Major contributors (alphabetic order):</h2>
+^<ul><h3>
+^<li> Hans-Bernhard Broeker
+^<li> John Campbell
+^<li> Robert Cunningham
+^<li> David Denholm
+^<li> Gershon Elber
+^<li> Roger Fearick
+^<li> Carsten Grammes
+^<li> Lucas Hart
+^<li> Lars Hecking
+^<li> Thomas Koenig
+^<li> David Kotz
+^<li> Ed Kubaitis
+^<li> Russell Lang
+^<li> Alexander Lehmann
+^<li> Alexander Mai
+^<li> Ethan A Merritt
+^<li> Petr Mikulik
+^<li> Carsten Steger
+^<li> Tom Tkacik
+^<li> Jos Van der Woude
+^<li> Alex Woo
+^<li> James R. Van Zandt
+^<li> Johannes Zellner
+^</h3></ul> <p>
+^<h2> Copyright (C) 1986 - 1993, 1998 - 2004 Thomas Williams, Colin Kelley<p>
+^ Mailing list for comments: gnuplot-info@lists.sourceforge.net <p>
+^ Mailing list for bug reports: gnuplot-bugs@lists.sourceforge.net <p>
+^</h2><p>
+^<h3> This manual was prepared by Dick Crawford</h3><p>
+^<h3> Last revised: February 2007</h3><p>
+^<hr>
+1 gnuplot
+2 Copyright
+?copyright
+?license
+ Copyright (C) 1986 - 1993, 1998, 2004, 2007 Thomas Williams, Colin Kelley
+
+ Permission to use, copy, and distribute this software and its
+ documentation for any purpose with or without fee is hereby granted,
+ provided that the above copyright notice appear in all copies and
+ that both that copyright notice and this permission notice appear
+ in supporting documentation.
+
+ Permission to modify the software is granted, but not the right to
+ distribute the complete modified source code. Modifications are to
+ be distributed as patches to the released version. Permission to
+ distribute binaries produced by compiling modified sources is granted,
+ provided you
+ 1. distribute the corresponding source modifications from the
+ released version in the form of a patch file along with the binaries,
+ 2. add special version identification to distinguish your version
+ in addition to the base release version number,
+ 3. provide your name and address as the primary contact for the
+ support of your modified version, and
+ 4. retain our contact information in regard to use of the base
+ software.
+ Permission to distribute the released version of the source code along
+ with corresponding source modifications in the form of a patch file is
+ granted with same provisions 2 through 4 for binary distributions.
+
+ This software is provided "as is" without express or implied warranty
+ to the extent permitted by applicable law.
+
+
+ AUTHORS
+
+ Original Software:
+ Thomas Williams, Colin Kelley.
+
+ Gnuplot 2.0 additions:
+ Russell Lang, Dave Kotz, John Campbell.
+
+ Gnuplot 3.0 additions:
+ Gershon Elber and many others.
+
+ Gnuplot 4.0 additions:
+ See list of contributors at head of this document.
+2 Introduction
+?introduction
+?
+ `gnuplot` is a command-driven interactive function and data plotting program.
+
+ Any command-line arguments are assumed to be names of files containing
+ `gnuplot` commands, with the exception of standard X11 arguments, which are
+ processed first. Each file is loaded with the `load` command, in the order
+ specified. `gnuplot` exits after the last file is processed. The special
+ filename "-" is used to denote standard input. When no load files are named,
+ `gnuplot` enters into an interactive mode. See help for `batch/interactive`
+ for more details.
+
+ `gnuplot` is case sensitive (commands and function names written in lowercase
+ are not the same as those written in CAPS). All command names may be
+ abbreviated as long as the abbreviation is not ambiguous. Any number of
+ commands may appear on a line (with the exception that `load` or `call` must
+ be the final command), separated by semicolons (;). Strings are indicated
+ with quotes. They may be either single or double quotation marks, e.g.,
+
+ load "filename"
+ cd 'dir'
+
+ although there are some subtle differences (see `syntax` for more details).
+
+ Many `gnuplot` commands have multiple options. Version 4 is less sensitive
+ to the order of these options than earlier versions, but some order-dependence
+ remains. If you see error messages about unrecognized options, please try
+ again using the exact order listed in the documentation.
+
+ Commands may extend over several input lines by ending each line but the last
+ with a backslash (\). The backslash must be the _last_ character on each
+ line. The effect is as if the backslash and newline were not there. That
+ is, no white space is implied, nor is a comment terminated. Therefore,
+ commenting out a continued line comments out the entire command
+ (see `comments`). But note that if an error occurs somewhere on a multi-line
+ command, the parser may not be able to locate precisely where the error is
+ and in that case will not necessarily point to the correct line.
+
+ In this document, curly braces ({}) denote optional arguments and a vertical
+ bar (|) separates mutually exclusive choices. `gnuplot` keywords or `help`
+ topics are indicated by backquotes or `boldface` (where available). Angle
+ brackets (<>) are used to mark replaceable tokens. In many cases, a default
+ value of the token will be taken for optional arguments if the token is
+ omitted, but these cases are not always denoted with braces around the angle
+ brackets.
+
+ For on-line help on any topic, type `help` followed by the name of the topic
+ or just `help` or `?` to get a menu of available topics.
+
+ The new `gnuplot` user should begin by reading about `plotting` (if on-line,
+ type `help plotting`).
+
+ See the simple.dem demo, also available together with other demos on the web page
+^ <a href="http://www.gnuplot.info/demo/simple.html">
+ http://www.gnuplot.info/demo/simple.html
+^ </a>
+2 Seeking-assistance
+^ <a name="Seeking-assistance"></a>
+?help-desk
+?seeking-assistance
+ There is a mailing list for `gnuplot` users. Note, however, that the
+ newsgroup
+ comp.graphics.apps.gnuplot
+ is identical to the mailing list (they both carry the same set of messages).
+ We prefer that you read the messages through the newsgroup rather than
+ subscribing to the mailing list. Instructions for subscribing to gnuplot
+ mailing lists may be found via the gnuplot development website on SourceForge
+^ <a href="http://sourceforge.net/projects/gnuplot">
+ http://sourceforge.net/projects/gnuplot
+^ </a>
+
+ The address for mailing to list members is:
+ gnuplot-info@lists.sourceforge.net
+
+ Bug reports and code contributions should be mailed to:
+ gnuplot-bugs@lists.sourceforge.net
+
+ The list of those interested in beta-test versions is:
+ gnuplot-beta@lists.sourceforge.net
+
+ There is also the canonical (if occasionally out-of-date) gnuplot web page at
+
+^ <a href="http://www.gnuplot.info">
+ http://www.gnuplot.info
+^ </a>
+
+ Before seeking help, please check the
+
+^ <a href="http://www.gnuplot.info/faq/">
+ FAQ (Frequently Asked Questions) list.
+^ </a>
+
+ When posting a question, please include full details of the version of
+ `gnuplot`, the machine, and operating system you are using. A _small_ script
+ demonstrating the problem may be useful. Function plots are preferable to
+ datafile plots. If email-ing to gnuplot-info, please state whether or not
+ you are subscribed to the list, so that users who use news will know to email
+ a reply to you. There is a form for such postings on the WWW site.
+
+2 New features introduced in version 4.2
+?new-features
+?version 4.2 features
+ Gnuplot version 4.2 offers many new features introduced since the preceding
+ official version 4.0. This section lists major additions and gives a partial
+ list of changes and minor new features. For a more exhaustive list, see the
+ NEWS file.
+
+3 New plot styles
+
+4 Histogram
+ Histograms, or bar charts, can be produced.
+ See `histograms`.
+
+4 Label plots
+ In coordination with the new `datastrings` feature described below, gnuplot
+ can draw a label at each vertex of a curve.
+ See `labels`.
+
+4 Image data
+ The `image` and `rgbimage` styles allow to plot 2D images (from ascii or
+ `binary` files) and map them in a 2D or 3D plot.
+ See `image` and `rgbimage`.
+
+4 Filled curves
+ The plot style `fillstyle` has been augmented to allow to fill the area
+ between two input curves with a color or a pattern.
+ See `filledcurves`.
+
+4 Vectors
+ Gnuplot can draw plots with vectors with a small arrowhead, requiring four or
+ six columns of data for 2D or 3D, respectively.
+ See `vectors`.
+
+3 Input from binary data files
+ Gnuplot can now read a generic `binary` input, including matrix binary and
+ `general binary` (until now gnuplot supported only its own `binary matrix`
+ format). Several matrix file formats are autodetected (`gpbin`, `edf`, `avs`).
+ Binary data files are mainly useful for `image` and `rgbimage` drawings.
+ See `binary` and `binary general filetype`.
+
+3 New plot elements
+
+4 RGB colors
+ Explicit RGB colors can be specified for all plot elements instead of
+ specifying a predefined linetype.
+ See `colorspec`.
+
+4 Arbitrary rectangles
+ You can place rectangles with desired fill style and border anywhere in a 2D
+ plot.
+ See `set object rectangle`.
+
+3 String handling
+4 String and text data read from datafiles
+ Gnuplot can now read and process text fields in datafiles.
+ See `datastrings`.
+4 User-defined string variables, operators, and functions
+ String variables and string functions are introduced. Most gnuplot commands
+ that previously required a string constant will now also accept a string
+ variable, a string expression, or a function that returns a string.
+ See `string variables`.
+
+3 Macros
+ Gnuplot supports command line macro expansion by '@stringvariablename'.
+ See `macros`.
+
+3 Auto-layout of multiple plots on a page
+ The `multiplot` mode is now able to layout automatically simple
+ multiplots without having to set the size or the position for each plot.
+ See `multiplot`.
+
+3 Internal variables
+ Gnuplot now exports several "read-only" variables such as GPVAL_TERM,
+ GPVAL_X_MIN, etc.
+ See `gnuplot-defined variables`.
+
+3 New or revised terminal drivers
+4 `wxt`
+ The `wxt` terminal is an interactive and cross-platform terminal for on-screen
+ rendering. It uses the wxWidgets library for its user interface, and Cairo
+ associated with Pango for the actual rendering, providing nice plots with
+ antialiasing on lines and text. The terminal supports the full range of
+ gnuplot capabilities, including mousing, pm3d plots, image plots and
+ enhanced text.
+4 `emf`
+ The `emf` terminal generates an Enhanced Metafile Format file. This file
+ format is the metafile standard on MS Win32 Systems. The emf terminal
+ supports pm3d, rgb color, and image plot modes.
+4 `gif`, `jpeg`, `png`
+ The code for the terminals using the `gd` library has been consolidated.
+ The `gif` terminal also knows how to produce an animated gif from a sequence
+ of plots.
+4 `postscript`
+ The `postscript` terminal can load prologue files, which can contain
+ additional user-defined sections with, for example, character encodings.
+ See `postscript prologue`.
+4 `ai`
+ The Adobe Illustrator `ai` driver is outdated. Since Adobe Illustrator
+ understands PostScript files, `set terminal post level1 ...` should be used
+ instead.
+4 `epslatex`, `pslatex`, `pstex`
+ The terminals supporting an output to latex augmented by PostScript commands
+ have been consolidated. Many options are the same as in the `postscript`
+ terminal.
+4 `windows`
+ The `windows` terminal now supports the `enhanced text` mode.
+
+3 Canvas size
+?canvas size
+?canvas
+?set term size
+
+ In earlier versions of gnuplot, some terminal types used the values from
+ `set size` to control also the size of the output canvas; others did not.
+ The use of 'set size' for this purpose was deprecated in version 4.2.
+ In version 4.3 almost all terminals now behave as follows:
+
+ `set term <terminal_type> size <XX>, <YY>` controls the size of the output
+ file, or "canvas". Please see individual terminal documentation for allowed
+ values of the size parameters. By default, the plot will fill this canvas.
+
+ `set size <XX>, <YY>` scales the plot itself relative to the size of the
+ canvas. Scale values less than 1 will cause the plot to not fill the entire
+ canvas. Scale values larger than 1 will cause only a portion of the plot to
+ fit on the canvas. Please be aware that setting scale values larger than 1
+ may cause problems on some terminal types.
+
+ The major exception to this convention is the PostScript driver, which
+ by default continues to act as it has in earlier versions. Be warned that
+ the next version of gnuplot may change the default behaviour of the
+ PostScript driver as well.
+
+ Example:
+
+ set size 0.5, 0.5
+ set term png size 600, 400
+ set output "figure.png"
+ plot "data" with lines
+
+ These commands will produce an output file "figure.png" that is 600 pixels
+ wide and 400 pixels tall. The plot will fill the lower left quarter of this
+ canvas. This is consistent with the way multiplot mode has always worked,
+ however it is a change in the way the png driver worked for single plots in
+ version 4.0.
+
+2 Backwards compatibility
+?backwards compatibility
+?compatibility
+ Gnuplot version 4.0 deprecated certain syntax used in earlier versions, but
+ continued to recognize it. This is now under the control of a configuration
+ option, and can be disabled as follows:
+
+ ./configure --disable-backwards-compatibility
+
+ Notice: Deprecated syntax items may be disabled permanently in some future
+ version of gnuplot.
+
+ One major difference is the introduction of keywords to disambiguate complex
+ commands, particularly commands containing string variables. A notable issue
+ was the use of bare numbers to specify offsets, line and point types.
+ Illustrative examples:
+
+ Deprecated:
+ set title "Old" 0,-1
+ set data linespoints
+ plot 1 2 4 # horizontal line at y=1
+ New:
+ TITLE = "New"
+ set title TITLE offset char 0, char -1
+ set style data linespoints
+ plot 1 linetype 2 pointtype 4
+
+ Another compatibility issue is the effect of the command `set size` outside
+ when not in multiplot mode. In earlier versions, the command
+ `set size <xx>, <yy>` caused some terminals to change both the size of the plot
+ and the size of the canvas is was drawn on; other terminatls changed only the
+ plot size. The use of `set size` to change the canvas size is now deprecated.
+
+ Please see `set size`, `set term size` and also the documentation for
+ individual terminals.
+
+2 Features introduced in version 4.0
+?version 4 features
+ Gnuplot version 4.0 contained many features introduced since the preceding
+ official version 3.7. These are summarized here.
+
+3 Mouse and hotkey support in interactive terminals
+
+ Interaction with the current plot via mouse and hotkeys is supported for the
+ X11, OS/2 Presentation Manager, ggi, Windows, and wxWidgets terminals. See
+ `mouse input` for more information on mousing. See help for `bind` for
+ information on hotkeys. Also see the documentation for individual mousing
+ terminals `ggi`, `pm`, `windows`, `wxt` and `x11`.
+
+ Sample script: mousevariables.dem
+
+3 New terminals
+
+ `aqua`: New terminal for Mac OS X. Requires AquaTerm 1.0 or later.
+
+ `epslatex`: New terminal. Prepares eps figures for inclusion in LaTeX
+ documents.
+
+ `gif`: Consolidated with png/jpeg terminals. Requires libgd.
+
+ `ggi`: New full-screen interactive terminal for Linux. Interface to the
+ General Graphics Interface Library.
+
+ `pdf`: New terminal exporting Adobe Portable Document Format. Requires libpdf.
+
+ `png` and `jpeg`: Support for GIF, PNG and JPEG image output is provided by a
+ new driver via libgd. The new driver supports many more features than the
+ old png driver, including TrueType fonts. Requires libgd.
+
+ `svg`: New terminal exporting Scalable Vector Graphics.
+
+3 New plot style `pm3d`
+
+ The `splot` command is now capable of plotting 2D maps and 3D surfaces
+ colored by greyscale or color palettes. See help for `set pm3d`, `set palette`,
+ `set cbrange`, `set view map`, `set colorbox` and `test palette`.
+
+ Sample scripts: pm3d.dem pm3dcolors.dem pm3dgamma.dem
+
+3 Filled boxes
+
+ A solid color or patterned fill style can be set for any plot style that
+ contains boxes. See `boxes`, `boxerrorbars`, `boxxyerrorbars`,
+ `candlesticks`, `set style fill`.
+
+ Sample scripts: fillstyle.dem candlesticks.dem
+
+3 New plot option smooth frequency
+
+ Input data can be filtered through several built-in routines for interpolation
+ or approximation of data. See `smooth`, `frequency`, `unique`.
+
+ Sample scripts: steps.dem mgr.dem
+
+3 Improved text options
+
+ Most gnuplot plot commands that produce text labels now accept modifiers to
+ specify text color, font, size, and rotation angle. See `set label`.
+ Not all terminal types support these options, however. The enhanced text
+ mode previously available for the postscript and pm terminals has been
+ extended to other terminal types as well. Terminal types currently supported
+ include aqua, dumb, jpeg, pdf, pm, png, postscript, x11, windows, and wxt.
+ See `enhanced text`.
+
+ Sample scripts: textcolor.dem textrotate.dem
+
+3 More text encodings
+
+ Several terminals, including `postscript`, `x11` and `pm`, support additional
+ text `encodings`: ISO 8859-1 (Latin 1), ISO 8859-2 (Latin 2), ISO 8859-15
+ (variant of 8859-1 with Euro sign), KOI8-R and KOI8-U (cyrillic), and
+ miscellaneous codepages. See `encoding` for more details.
+
+3 Arrows
+
+ Single- or double-ended arrows can be placed on a plot individually from the
+ command line or from a data file via the `plot with vectors` style.
+ See `set style arrow`, `plotting styles vectors`.
+
+ Sample scripts: arrowstyle.dem vector.dem
+
+3 Data file format
+
+ The new `set datafile` command can be used to specify information about the
+ format of input data files, including the characters used to separate fields,
+ to indicate comment lines, and to specify missing data. Gnuplot now attempts
+ to recognize text fields with embedded blanks as single entities based on the
+ datafile format settings. This allows input from csv (comma-separated value)
+ files such as those exported by spreadsheet programs. See `set datafile`.
+ See also the `binary` option (introduced in 4.2).
+
+3 New commands
+
+ `set view map` selects a top-view 2D projection of 3D surface plot.
+
+ `set term push` and `set term pop` save and restore the current terminal type.
+
+ `load` and `save` commands accept piped input and output, respectively.
+
+3 Other changes and additions
+
+ Since gnuplot 4.0, `unset <something>` is preferred to `set no<something>`.
+ The older form has been deprecated.
+ Version 4.2 continues to allow the older syntax, but such backwards
+ compatibility may be lost in future versions.
+
+ Commands of the form `set <something> <style>` also are deprecated in favor
+ of the more general form `set style <something> <options>`. Many more plot
+ elements now have style options of their own, including arrows, filled
+ areas, lines, and points. There are also style settings for input data and
+ formatting. Please see `set style`, `set decimalsign`, and `set datafile`.
+
+ The MS Windows package includes an additional executable `pgnuplot.exe` to
+ support piping command through standard input, which is otherwise not
+ available for graphical applications on this system.
+
+3 Accompanying documentation
+
+ In directory docs/psdocs/ you may find new information in the gnuplot output
+ postscript file guide, list of postscript symbols in different encodings.
+
+ Improved FAQ. Please read it before asking your question in a public forum.
+
+ There are plenty of new demos *.dem in the demo/ directory. Please run them,
+ for example by
+ load "all.dem"
+ before asking for help. Plots produced by the demo scripts can also be viewed
+ at
+^ <a href="http://www.gnuplot.info/demo/">
+ http://www.gnuplot.info/demo/
+^ </a>
+
+2 Batch/Interactive Operation
+?batch/interactive
+ `gnuplot` may be executed in either batch or interactive modes, and the two
+ may even be mixed together on many systems.
+
+ Any command-line arguments are assumed to be names of files containing
+ `gnuplot` commands (with the exception of standard X11 arguments, which are
+ processed first). Each file is loaded with the `load` command, in the order
+ specified. `gnuplot` exits after the last file is processed. When no load
+ files are named, `gnuplot` enters into an interactive mode. The special
+ filename "-" is used to denote standard input.
+
+ Both the `exit` and `quit` commands terminate the current command file and
+ `load` the next one, until all have been processed.
+
+ Examples:
+
+ To launch an interactive session:
+ gnuplot
+
+ To launch a batch session using two command files "input1" and "input2":
+ gnuplot input1 input2
+
+ To launch an interactive session after an initialization file "header" and
+ followed by another command file "trailer":
+ gnuplot header - trailer
+2 Command-line-editing
+?line-editing
+?editing
+?command-line-editing
+ Command-line editing is supported by the Unix, Atari, VMS, MS-DOS and OS/2
+ versions of `gnuplot`. Also, a history mechanism allows previous commands to
+ be edited and re-executed. After the command line has been edited, a newline
+ or carriage return will enter the entire line without regard to where the
+ cursor is positioned.
+
+ (The readline function in `gnuplot` is not the same as the readline used in
+ GNU Bash and GNU Emacs. If the GNU version is desired, it may be selected
+ instead of the `gnuplot` version at compile time.)
+
+
+ The editing commands are as follows:
+
+@start table - first is interactive cleartext form
+ `Line-editing`:
+
+ ^B moves back a single character.
+ ^F moves forward a single character.
+ ^A moves to the beginning of the line.
+ ^E moves to the end of the line.
+ ^H and DEL delete the previous character.
+ ^D deletes the current character.
+ ^K deletes from current position to the end of line.
+ ^L,^R redraws line in case it gets trashed.
+ ^U deletes the entire line.
+ ^W deletes from the current word to the end of line.
+
+ `History`:
+
+ ^P moves back through history.
+ ^N moves forward through history.
+#\begin{tabular}{|cl|} \hline
+#\multicolumn{2}{|c|}{Command-line Editing Commands} \\ \hline \hline
+#Character & Function \\ \hline
+# & \multicolumn{1}{|c|}{Line Editing}\\ \cline{2-2}
+#\verb~^B~ & move back a single character.\\
+#\verb~^F~ & move forward a single character.\\
+#\verb~^A~ & move to the beginning of the line.\\
+#\verb~^E~ & move to the end of the line.\\
+#\verb~^H, DEL~ & delete the previous character.\\
+#\verb~^D~ & delete the current character.\\
+#\verb~^K~ & delete from current position to the end of line.\\
+#\verb~^L, ^R~ & redraw line in case it gets trashed.\\
+#\verb~^U~ & delete the entire line. \\
+#\verb~^W~ & delete from the current word to the end of line. \\ \hline
+# & \multicolumn{1}{|c|}{History} \\ \cline{2-2}
+#\verb~^P~ & move back through history.\\
+#\verb~^N~ & move forward through history.\\
+%c l .
+%Character@Function
+%_
+%@Line Editing
+%^B@move back a single character.
+%^F@move forward a single character.
+%^A@move to the beginning of the line.
+%^E@move to the end of the line.
+%^H, DEL@delete the previous character.
+%^D@delete the current character.
+%^K@delete from current position to the end of line.
+%^L, ^R@redraw line in case it gets trashed.
+%^U@delete the entire line.
+%^W@delete from the current word to the end of line.
+%_
+%@History
+%^P@move back through history.
+%^N@move forward through history.
+@end table
+
+ On the IBM PC, the use of a TSR program such as DOSEDIT or CED may be desired
+ for line editing. The default makefile assumes that this is the case; by
+ default `gnuplot` will be compiled with no line-editing capability. If you
+ want to use `gnuplot`'s line editing, set READLINE in the makefile and add
+ readline.obj to the link file. The following arrow keys may be used on the
+ IBM PC and Atari versions if readline is used:
+
+@start table - first is interactive cleartext form
+ Left Arrow - same as ^B.
+ Right Arrow - same as ^F.
+ Ctrl Left Arrow - same as ^A.
+ Ctrl Right Arrow - same as ^E.
+ Up Arrow - same as ^P.
+ Down Arrow - same as ^N.
+#\begin{tabular}{|cl|} \hline
+#Arrow key & Function \\ \hline
+#Left & same as \verb~^B~. \\
+#Right & same as \verb~^F~. \\
+#Ctrl Left & same as \verb~^A~. \\
+#Ctrl Right & same as \verb~^E~. \\
+#Up & same as \verb~^P~. \\
+#Down & same as \verb~^N~. \\
+%c l .
+%Arrow key@Function
+%_
+%Left Arrow@same as ^B.
+%Right Arrow@same as ^F.
+%Ctrl Left Arrow@same as ^A.
+%Ctrl Right Arrow@same as ^E.
+%Up Arrow@same as ^P.
+%Down Arrow@same as ^N.
+%_
+@end table
+
+ The Atari version of readline defines some additional key aliases:
+
+@start table - first is interactive cleartext form
+ Undo - same as ^L.
+ Home - same as ^A.
+ Ctrl Home - same as ^E.
+ Esc - same as ^U.
+ Help - `help` plus return.
+ Ctrl Help - `help`.
+#\begin{tabular}{|cl|} \hline
+#Key & Function \\ \hline
+#Undo & same as \verb~^L~. \\
+#Home & same as \verb~^A~. \\
+#Ctrl Home & same as \verb~^E~. \\
+#Esc & same as \verb~^U~. \\
+#Help & `{\bf help}` plus return. \\
+#Ctrl Help & `{\bf help}`. \\
+%c l .
+%Key@Function
+%_
+%Undo@same as ^L.
+%Home@same as ^A.
+%Ctrl Home@same as ^E.
+%Esc@same as ^U.
+%Help@help plus return.
+%Ctrl Help@help .
+%_
+@end table
+2 Comments
+?comments
+ Comments are supported as follows: a `#` may appear in most places in a line
+ and `gnuplot` will ignore the rest of the line. It will not have this effect
+ inside quotes, inside numbers (including complex numbers), inside command
+ substitutions, etc. In short, it works anywhere it makes sense to work.
+
+ See also `set datafile commentschars` for specifying comment characters in
+ data files.
+2 Coordinates
+?coordinates
+ The commands `set arrow`, `set key`, `set label` and `set object` allow you
+ to draw something at an arbitrary position on the graph. This position is
+ specified by the syntax:
+
+ {<system>} <x>, {<system>} <y> {,{<system>} <z>}
+
+ Each <system> can either be `first`, `second`, `graph`, `screen`, or
+ `character`.
+
+ `first` places the x, y, or z coordinate in the system defined by the left
+ and bottom axes; `second` places it in the system defined by the second axes
+ (top and right); `graph` specifies the area within the axes---0,0 is bottom
+ left and 1,1 is top right (for splot, 0,0,0 is bottom left of plotting area;
+ use negative z to get to the base---see `set ticslevel`); `screen`
+ specifies the screen area (the entire area---not just the portion selected by
+ `set size`), with 0,0 at bottom left and 1,1 at top right; and `character`
+ gives the position in character widths and heights from the bottom left of
+ the screen area (screen 0,0), `character` coordinates depend on the chosen
+ font size.
+
+ If the coordinate system for x is not specified, `first` is used. If the
+ system for y is not specified, the one used for x is adopted.
+
+ In some cases, the given coordinate is not an absolute position but a
+ relative value (e.g., the second position in `set arrow` ... `rto`). In
+ most cases, the given value serves as difference to the first position.
+ If the given coordinate resides in a logarithmic axis the value is
+ interpreted as factor. For example,
+
+ set logscale x
+ set arrow 100,5 rto 10,2
+
+ plots an arrow from position 100,5 to position 1000,7 since the x axis is
+ logarithmic while the y axis is linear.
+
+ If one (or more) axis is timeseries, the appropriate coordinate should
+ be given as a quoted time string according to the `timefmt` format string.
+ See `set xdata` and `set timefmt`. `gnuplot` will also accept an integer
+ expression, which will be interpreted as seconds from 1 January 2000.
+2 Datastrings
+?datastrings
+ The configuration option --enable-datastrings allows gnuplot to read and
+ process text fields in datafiles. A text field consists of either an arbitrary
+ string of printable characters containing no whitespace or an arbitrary string
+ of characters, possibly including whitespace, delimited by double quotes.
+ The following sample line from a datafile is interpreted to contain four
+ columns, with a text field in column 3:
+
+ 1.000 2.000 "Third column is all of this text" 4.00
+
+ Text fields can be positioned within a 2-D or 3-D plot using the commands:
+
+ plot 'datafile' using 1:2:4 with labels
+ splot 'datafile using 1:2:3:4 with labels
+
+ A column of text data can also be used to label the ticmarks along one or more
+ of the plot axes. The example below plots a line through a series of points
+ with (X,Y) coordinates taken from columns 3 and 4 of the input datafile.
+ However, rather than generating regularly spaced tics along the x axis
+ labeled numerically, gnuplot will position a tic mark along the x axis at the
+ X coordinate of each point and label the tic mark with text taken from column
+ 1 of the input datafile.
+
+ set xtics
+ plot 'datafile' using 3:4:xticlabels(1) with linespoints
+
+ There is also an option that will interpret the first entry in a column of
+ input data as a text field, and use it as the key title for data plotted from
+ that column. The example given below will use the first entry in column 2 to
+ generate a title in the key box, while processing the remainder of columns
+ 2 and 4 to draw the required line:
+
+ plot 'datafile' using 1:(f($2)/$4) title 2 with lines
+
+ See `set style labels`, `using xticlabels`, `plot title`, `using`.
+2 Environment
+?environment
+ A number of shell environment variables are understood by `gnuplot`. None of
+ these are required, but may be useful.
+
+ If GNUTERM is defined, it is used as the name of the terminal type to be
+ used. This overrides any terminal type sensed by `gnuplot` on start-up, but
+ is itself overridden by the .gnuplot (or equivalent) start-up file
+ (see `start-up`) and, of course, by later explicit changes.
+
+ On Unix, AmigaOS, AtariTOS, MS-DOS and OS/2, GNUHELP may be defined to be the
+ pathname of the HELP file (gnuplot.gih).
+
+ On VMS, the logical name GNUPLOT$HELP should be defined as the name of the
+ help library for `gnuplot`. The `gnuplot` help can be put inside any system
+ help library, allowing access to help from both within and outside `gnuplot`
+ if desired.
+
+ On Unix, HOME is used as the name of a directory to search for a .gnuplot
+ file if none is found in the current directory. On AmigaOS, AtariTOS,
+ MS-DOS, Windows and OS/2, GNUPLOT is used. On Windows, the NT-specific
+ variable USERPROFILE is tried, too. VMS, SYS$LOGIN: is used. Type `help
+ start-up`.
+
+ On Unix, PAGER is used as an output filter for help messages.
+
+ On Unix, AtariTOS and AmigaOS, SHELL is used for the `shell` command. On
+ MS-DOS and OS/2, COMSPEC is used for the `shell` command.
+
+ On MS-DOS, if the BGI or Watcom interface is used, PCTRM is used to tell
+ the maximum resolution supported by your monitor by setting it to
+ S<max. horizontal resolution>. E.g. if your monitor's maximum resolution is
+ 800x600, then use:
+ set PCTRM=S800
+ If PCTRM is not set, standard VGA is used.
+
+ FIT_SCRIPT may be used to specify a `gnuplot` command to be executed when a
+ fit is interrupted---see `fit`. FIT_LOG specifies the default filename of the
+ logfile maintained by fit.
+
+ GNUPLOT_LIB may be used to define additional search directories for data
+ and command files. The variable may contain a single directory name, or
+ a list of directories separated by a platform-specific path separator,
+ eg. ':' on Unix, or ';' on DOS/Windows/OS/2/Amiga platforms. The contents
+ of GNUPLOT_LIB are appended to the `loadpath` variable, but not saved
+ with the `save` and `save set` commands.
+
+ Several gnuplot terminal drivers access TrueType fonts via the gd library.
+ For these drivers the font search path is controlled by the environmental
+ variable GDFONTPATH. Furthermore, a default font for these drivers may be
+ set via the environmental variable GNUPLOT_DEFAULT_GDFONT.
+
+ The postscript terminal uses its own font search path. It is controlled by
+ the environmental variable GNUPLOT_FONTPATH. The format is the same as for
+ GNUPLOT_LIB. The contents of GNUPLOT_FONTPATH are appended to the `fontpath`
+ variable, but not saved with the `save` and `save set` commands.
+
+ GNUPLOT_PS_DIR is used by the postscript driver to use external prologue
+ files. Depending on the build process, gnuplot contains either a builtin
+ copy of those files or simply a default hardcoded path. Use this variable
+ to test the postscript terminal with custom prologue files. See
+ `postscript prologue`.
+2 Expressions
+?expressions
+ In general, any mathematical expression accepted by C, FORTRAN, Pascal, or
+ BASIC is valid. The precedence of these operators is determined by the
+ specifications of the C programming language. White space (spaces and tabs)
+ is ignored inside expressions.
+
+ Complex constants are expressed as {<real>,<imag>}, where <real> and <imag>
+ must be numerical constants. For example, {3,2} represents 3 + 2i; {0,1}
+ represents 'i' itself. The curly braces are explicitly required here.
+
+ Note that gnuplot uses both "real" and "integer" arithmetic, like FORTRAN and
+ C. Integers are entered as "1", "-10", etc; reals as "1.0", "-10.0", "1e1",
+ 3.5e-1, etc. The most important difference between the two forms is in
+ division: division of integers truncates: 5/2 = 2; division of reals does
+ not: 5.0/2.0 = 2.5. In mixed expressions, integers are "promoted" to reals
+ before evaluation: 5/2e0 = 2.5. The result of division of a negative integer
+ by a positive one may vary among compilers. Try a test like "print -5/2" to
+ determine if your system chooses -2 or -3 as the answer.
+
+ The integer expression "1/0" may be used to generate an "undefined" flag,
+ which causes a point to ignored; the `ternary` operator gives an example.
+ Or you can use the pre-defined variable NaN to achieve the same result.
+=NaN
+
+ The real and imaginary parts of complex expressions are always real, whatever
+ the form in which they are entered: in {3,2} the "3" and "2" are reals, not
+ integers.
+
+ Gnuplot can also perform simple operations on strings and string variables.
+ For example, the expression ("A" . "B" eq "AB") evaluates as true, illustrating
+ the string concatenation operator and the string equality operator.
+
+ A string which contains a numerical value is promoted to the corresponding
+ integer or real value if used in a numerical expression. Thus ("3" + "4" == 7)
+ and (6.78 == "6.78") both evaluate to true. An integer, but not a real or
+ complex value, is promoted to a string if used in string concatenation.
+ A typical case is the use of integers to construct file names or other strings;
+ e.g. ("file" . 4 eq "file4") is true.
+
+ Substrings can be specified using a postfixed range descriptor [beg:end].
+ For example, "ABCDEF"[3:4] == "CD" and "ABCDEF"[4:*] == "DEF"
+ The syntax "string"[beg:end] is exactly equivalent to calling the built-in
+ string-valued function substr("string",beg,end), except that you cannot
+ omit either beg or end from the function call.
+3 Functions
+?expressions functions
+?functions
+ The functions in `gnuplot` are the same as the corresponding functions in
+ the Unix math library, except that all functions accept integer, real, and
+ complex arguments, unless otherwise noted.
+
+ For those functions that accept or return angles that may be given in either
+ degrees or radians (sin(x), cos(x), tan(x), asin(x), acos(x), atan(x),
+ atan2(x) and arg(z)), the unit may be selected by `set angles`, which
+ defaults to radians.
+
+@start table
+#\begin{tabular}{|ccl|} \hline
+#\multicolumn{3}{|c|}{Math library functions} \\ \hline \hline
+#Function & Arguments & Returns \\ \hline
+%c c l .
+%Function@Arguments@Returns
+%_
+4 abs
+?expressions functions abs
+?functions abs
+?abs
+#abs(x) & any & absolute value of $x$, $|x|$; same type \\
+#abs(x) & complex & length of $x$, $\sqrt{{\mbox{real}(x)^{2} +
+#\mbox{imag}(x)^{2}}}$ \\
+%abs(x)@any@absolute value of $x$, $|x|$; same type
+%abs(x)@complex@length of $x$, $sqrt{roman real (x) sup 2 + roman imag (x) sup 2}$
+ The `abs(x)` function returns the absolute value of its argument. The
+ returned value is of the same type as the argument.
+
+ For complex arguments, abs(x) is defined as the length of x in the complex
+ plane [i.e., sqrt(real(x)**2 + imag(x)**2) ].
+4 acos
+?expressions functions acos
+?functions acos
+?acos
+#acos(x) & any & $\cos^{-1} x$ (inverse cosine) \\
+%acos(x)@any@$cos sup -1 x$ (inverse cosine)
+ The `acos(x)` function returns the arc cosine (inverse cosine) of its
+ argument. `acos` returns its argument in radians or degrees, as selected by
+ `set angles`.
+4 acosh
+?expressions functions acosh
+?functions acosh
+?acosh
+#acosh(x) & any & $\cosh^{-1} x$ (inverse hyperbolic cosine) in radians \\
+%acosh(x)@any@$cosh sup -1 x$ (inverse hyperbolic cosine) in radians
+ The `acosh(x)` function returns the inverse hyperbolic cosine of its argument
+ in radians.
+4 arg
+?expressions functions arg
+?functions arg
+?arg
+#arg(x) & complex & the phase of $x$ \\
+%arg(x)@complex@the phase of $x$
+ The `arg(x)` function returns the phase of a complex number in radians or
+ degrees, as selected by `set angles`.
+4 asin
+?expressions functions asin
+?functions asin
+?asin
+#asin(x) & any & $\sin^{-1} x$ (inverse sin) \\
+%asin(x)@any@$sin sup -1 x$ (inverse sin)
+ The `asin(x)` function returns the arc sin (inverse sin) of its argument.
+ `asin` returns its argument in radians or degrees, as selected by `set
+ angles`.
+4 asinh
+?expressions functions asinh
+?functions asinh
+?asinh
+#asinh(x) & any & $\sinh^{-1} x$ (inverse hyperbolic sin) in radians \\
+%asinh(x)@any@$sinh sup -1 x$ (inverse hyperbolic sin) in radians
+ The `asinh(x)` function returns the inverse hyperbolic sin of its argument in
+ radians.
+4 atan
+?expressions functions atan
+?functions atan
+?atan
+#atan(x) & any & $\tan^{-1} x$ (inverse tangent) \\
+%atan(x)@any@$tan sup -1 x$ (inverse tangent)
+ The `atan(x)` function returns the arc tangent (inverse tangent) of its
+ argument. `atan` returns its argument in radians or degrees, as selected by
+ `set angles`.
+4 atan2
+?expressions functions atan2
+?functions atan2
+?atan2
+#atan2(y,x) & int or real & $\tan^{-1} (y/x)$ (inverse tangent) \\
+%atan2(y,x)@int or real@$tan sup -1 (y/x)$ (inverse tangent)
+ The `atan2(y,x)` function returns the arc tangent (inverse tangent) of the
+ ratio of the real parts of its arguments. `atan2` returns its argument in
+ radians or degrees, as selected by `set angles`, in the correct quadrant.
+4 atanh
+?expressions functions atanh
+?functions atanh
+?atanh
+#atanh(x) & any & $\tanh^{-1} x$ (inverse hyperbolic tangent) in radians \\
+%atanh(x)@any@$tanh sup -1 x$ (inverse hyperbolic tangent) in radians
+ The `atanh(x)` function returns the inverse hyperbolic tangent of its
+ argument in radians.
+4 besj0
+?expressions functions besj0
+?functions besj0
+?besj0
+#besj0(x) & int or real & $j_{0}$ Bessel function of $x$, in radians \\
+%besj0(x)@int or real@$j sub 0$ Bessel function of $x$, in radians
+ The `besj0(x)` function returns the j0th Bessel function of its argument.
+ `besj0` expects its argument to be in radians.
+4 besj1
+?expressions functions besj1
+?functions besj1
+?besj1
+#besj1(x) & int or real & $j_{1}$ Bessel function of $x$, in radians \\
+%besj1(x)@int or real@$j sub 1$ Bessel function of $x$, in radians
+ The `besj1(x)` function returns the j1st Bessel function of its argument.
+ `besj1` expects its argument to be in radians.
+4 besy0
+?expressions functions besy0
+?functions besy0
+?besy0
+#besy0(x) & int or real & $y_{0}$ Bessel function of $x$, in radians \\
+%besy0(x)@int or real@$y sub 0$ Bessel function of $x$, in radians
+ The `besy0(x)` function returns the y0th Bessel function of its argument.
+ `besy0` expects its argument to be in radians.
+4 besy1
+?expressions functions besy1
+?functions besy1
+?besy1
+#besy1(x) & int or real & $y_{1}$ Bessel function of $x$, in radians \\
+%besy1(x)@int or real@$y sub 1$ Bessel function of $x$, in radians
+ The `besy1(x)` function returns the y1st Bessel function of its argument.
+ `besy1` expects its argument to be in radians.
+4 ceil
+?expressions functions ceil
+?functions ceil
+?ceil
+#ceil(x) & any & $\lceil x \rceil$, smallest integer not less than $x$
+#(real part) \\
+%ceil(x)@any@$left ceiling x right ceiling$, smallest integer not less than $x$ (real part)
+ The `ceil(x)` function returns the smallest integer that is not less than its
+ argument. For complex numbers, `ceil` returns the smallest integer not less
+ than the real part of its argument.
+4 cos
+?expressions functions cos
+?functions cos
+?cos
+#cos(x) & any & $\cos x$, cosine of $x$ \\
+%cos(x)@radians@$cos~x$, cosine of $x$
+ The `cos(x)` function returns the cosine of its argument. `cos` accepts its
+ argument in radians or degrees, as selected by `set angles`.
+4 cosh
+?expressions functions cosh
+?functions cosh
+?cosh
+#cosh(x) & any & $\cosh x$, hyperbolic cosine of $x$ in radians \\
+%cosh(x)@any@$cosh~x$, hyperbolic cosine of $x$ in radians
+ The `cosh(x)` function returns the hyperbolic cosine of its argument. `cosh`
+ expects its argument to be in radians.
+4 erf
+?expressions functions erf
+?functions erf
+?erf
+#erf(x) & any & $\mbox{erf}(\mbox{real}(x))$, error function of real($x$) \\
+%erf(x)@any@$erf ( roman real (x))$, error function of real ($x$)
+ The `erf(x)` function returns the error function of the real part of its
+ argument. If the argument is a complex value, the imaginary component is
+ ignored. See `erfc`, `inverf`, and `norm`.
+4 erfc
+?expressions functions erfc
+?functions erfc
+?erfc
+#erfc(x) & any & $\mbox{erfc}(\mbox{real}(x))$, 1.0 - error function of real($x$) \\
+%erfc(x)@any@$erfc ( roman real (x))$, 1.0 - error function of real ($x$)
+ The `erfc(x)` function returns 1.0 - the error function of the real part of
+ its argument. If the argument is a complex value, the imaginary component is
+ ignored. See `erf`, `inverf`, and `norm`.
+4 exp
+?expressions functions exp
+?functions exp
+?exp
+#exp(x) & any & $e^{x}$, exponential function of $x$ \\
+%exp(x)@any@$e sup x$, exponential function of $x$
+ The `exp(x)` function returns the exponential function of its argument (`e`
+ raised to the power of its argument). On some implementations (notably
+ suns), exp(-x) returns undefined for very large x. A user-defined function
+ like safe(x) = x<-100 ? 0 : exp(x) might prove useful in these cases.
+4 floor
+?expressions functions floor
+?functions floor
+?floor
+#floor(x) & any & $\lfloor x \rfloor$, largest integer not greater
+#than $x$ (real part) \\
+%floor(x)@any@$left floor x right floor$, largest integer not greater than $x$ (real part)
+ The `floor(x)` function returns the largest integer not greater than its
+ argument. For complex numbers, `floor` returns the largest integer not
+ greater than the real part of its argument.
+4 gamma
+?expressions functions gamma
+?functions gamma
+?gamma
+#gamma(x) & any & $\mbox{gamma}(\mbox{real}(x))$, gamma function of real($x$) \\
+%gamma(x)@any@$GAMMA ( roman real (x))$, gamma function of real ($x$)
+ The `gamma(x)` function returns the gamma function of the real part of its
+ argument. For integer n, gamma(n+1) = n!. If the argument is a complex
+ value, the imaginary component is ignored.
+4 ibeta
+?expressions functions ibeta
+?functions ibeta
+?ibeta
+#ibeta(p,q,x) & any & $\mbox{ibeta}(\mbox{real}(p,q,x))$, ibeta function of real($p$,$q$,$x$) \\
+%ibeta(p,q,x)@any@$ibeta ( roman real (p,q,x))$, ibeta function of real ($p$,$q$,$x$)
+ The `ibeta(p,q,x)` function returns the incomplete beta function of the real
+ parts of its arguments. p, q > 0 and x in [0:1]. If the arguments are
+ complex, the imaginary components are ignored.
+4 inverf
+?expressions functions inverf
+?functions inverf
+?inverf
+#inverf(x) & any & inverse error function of real($x$) \\
+%inverf(x)@any@inverse error function real($x$)
+ The `inverf(x)` function returns the inverse error function of the real part
+ of its argument. See `erf` and `invnorm`.
+4 igamma
+?expressions functions igamma
+?functions igamma
+?igamma
+#igamma(a,x) & any & $\mbox{igamma}(\mbox{real}(a,x))$, igamma function of real($a$,$x$) \\
+%igamma(a,x)@any@$igamma ( roman real (a,x))$, igamma function of real ($a$,$x$)
+ The `igamma(a,x)` function returns the normalized incomplete gamma
+ function of the real parts of its arguments, where a > 0 and x >= 0.
+ The standard notation is P(a,x), e.g. Abramowitz and Stegun (6.5.1),
+ with limiting value of 1 as x approaches infinity. If the arguments
+ are complex, the imaginary components are ignored.
+4 imag
+?expressions functions imag
+?functions imag
+?imag
+#imag(x) & complex & imaginary part of $x$ as a real number \\
+%imag(x)@complex@imaginary part of $x$ as a real number
+ The `imag(x)` function returns the imaginary part of its argument as a real
+ number.
+4 invnorm
+?expressions functions invnorm
+?functions invnorm
+?invnorm
+#invnorm(x) & any & inverse normal distribution function of real($x$) \\
+%invnorm(x)@any@inverse normal distribution function real($x$)
+ The `invnorm(x)` function returns the inverse cumulative normal (Gaussian)
+ distribution function of the real part of its argument. See `norm`.
+4 int
+?expressions functions int
+?functions int
+?int
+#int(x) & real & integer part of $x$, truncated toward zero \\
+%int(x)@real@integer part of $x$, truncated toward zero
+ The `int(x)` function returns the integer part of its argument, truncated
+ toward zero.
+4 lambertw
+?expressions functions lambertw
+?functions lambertw
+?lambertw
+#lambertw(x) & real & Lambert W function \\
+%lambertw(x)@real@Lambert W function
+ The lambertw function returns the value of the principal branch of
+ Lambert's W function, which is defined by the equation (W(z)*exp(W(z))=z.
+ z must be a real number with z >= -exp(-1).
+4 lgamma
+?expressions functions lgamma
+?functions lgamma
+?lgamma
+#lgamma(x) & any & $\mbox{lgamma}(\mbox{real}(x))$, lgamma function of real($x$) \\
+%lgamma(x)@any@$lgamma ( roman real (x))$, lgamma function of real ($x$)
+ The `lgamma(x)` function returns the natural logarithm of the gamma function
+ of the real part of its argument. If the argument is a complex value, the
+ imaginary component is ignored.
+4 log
+?expressions functions log
+?functions log
+?log
+#log(x) & any & $\log_{e} x$, natural logarithm (base $e$) of $x$ \\
+%log(x)@any@$ln~x$, natural logarithm (base $e$) of $x$
+ The `log(x)` function returns the natural logarithm (base `e`) of its
+ argument. See `log10`.
+4 log10
+?expressions functions log10
+?functions log10
+?log10
+#log10(x) & any & $\log_{10} x$, logarithm (base $10$) of $x$ \\
+%log10(x)@any@${log sub 10}~x$, logarithm (base $10$) of $x$
+ The `log10(x)` function returns the logarithm (base 10) of its argument.
+4 norm
+?expressions functions norm
+?functions norm
+?norm
+#norm(x) & any & normal distribution (Gaussian) function of real($x$) \\
+%norm(x)@any@$norm(x)$, normal distribution function of real($x$)
+ The `norm(x)` function returns the cumulative normal (Gaussian) distribution
+ function of the real part of its argument. See `invnorm`, `erf` and `erfc`.
+4 rand
+?expressions functions rand
+?functions rand
+?rand
+#rand(x) & any & $\mbox{rand}(x)$, pseudo random number generator \\
+%rand(x)@any@$rand (x)$, pseudo random number generator
+ `rand(0)` returns a pseudo random number in the interval [0:1] generated
+ from the current value of two internal 32-bit seeds.
+ `rand(-1)` resets both seeds to a standard value.
+ `rand(x)` for x>0 sets both seeds to a value based on the value of x.
+ `rand({x,y})` for x>0 sets seed1 to x and seed2 to y.
+ Note: This behavior has changed starting with gnuplot version 3.8l. Older
+ scripts that expected rand(x>0) to produce sequential pseudo-random numbers
+ from the same seeded sequence must be changed to call rand(0) instead.
+4 real
+?expressions functions real
+?functions real
+?real
+#real(x) & any & real part of $x$ \\
+%real(x)@any@real part of $x$
+ The `real(x)` function returns the real part of its argument.
+4 sgn
+?expressions functions sgn
+?functions sgn
+?sgn
+#sgn(x) & any & 1 if $x>0$, -1 if $x<0$, 0 if $x=0$. imag($x$) ignored \\
+%sgn(x)@any@1 if $x > 0$, -1 if $x < 0$, 0 if $x = 0$. $roman imag (x)$ ignored
+ The `sgn(x)` function returns 1 if its argument is positive, -1 if its
+ argument is negative, and 0 if its argument is 0. If the argument is a
+ complex value, the imaginary component is ignored.
+4 sin
+?expressions functions sin
+?functions sin
+?sin
+#sin(x) & any & $\sin x$, sine of $x$ \\
+%sin(x)@any@$sin~x$, sine of $x$
+ The `sin(x)` function returns the sine of its argument. `sin` expects its
+ argument to be in radians or degrees, as selected by `set angles`.
+4 sinh
+?expressions functions sinh
+?functions sinh
+?sinh
+#sinh(x) & any & $\sinh x$, hyperbolic sine of $x$ in radians \\
+%sinh(x)@any@$sinh~x$, hyperbolic sine of $x$ in radians
+ The `sinh(x)` function returns the hyperbolic sine of its argument. `sinh`
+ expects its argument to be in radians.
+4 sqrt
+?expressions functions sqrt
+?functions sqrt
+?sqrt
+#sqrt(x) & any & $\sqrt{x}$, square root of $x$ \\
+%sqrt(x)@any@$sqrt x $, square root of $x$
+ The `sqrt(x)` function returns the square root of its argument.
+4 tan
+?expressions functions tan
+?functions tan
+?tan
+#tan(x) & any & $\tan x$, tangent of $x$ \\
+%tan(x)@any@$tan~x$, tangent of $x$
+ The `tan(x)` function returns the tangent of its argument. `tan` expects
+ its argument to be in radians or degrees, as selected by `set angles`.
+4 tanh
+?expressions functions tanh
+?functions tanh
+?tanh
+#tanh(x) & any & $\tanh x$, hyperbolic tangent of $x$ in radians\\
+%tanh(x)@any@$tanh~x$, hyperbolic tangent of $x$ in radians
+ The `tanh(x)` function returns the hyperbolic tangent of its argument. `tanh`
+ expects its argument to be in radians.
+@end table
+
+@start table
+#\begin{tabular}{|ccl|} \hline
+#\multicolumn{3}{|c|}{String functions} \\ \hline \hline
+#Function & Arguments & Returns \\ \hline
+%c c l .
+%Function@Arguments@Returns
+%_
+4 gprintf
+?expressions functions gprintf
+?functions gprintf
+#gprintf("format",x) & any & string result from applying gnuplot's format parser \\
+%gprintf("format",x)@any@string result from applysing gnuplot's format parser
+ `gprintf("format",x)` applies gnuplot's own format specifiers to the single
+ variable x and returns the resulting string. If you want standard C-language
+ format specifiers, you must instead use `sprintf("format",x)`.
+ See `format specifiers`.
+4 sprintf
+?expressions functions sprintf
+?functions sprintf
+?sprintf
+#sprintf("format",x,...) & multiple & string result from C-language sprintf \\
+%sprintf("format",x,...)@multiple@string result from C-language sprintf
+ `sprintf("format",var1,var2,...)` applies standard C-language format specifiers
+ to multiple arguments (10 max) and returns the resulting string. If you want to
+ use gnuplot's own format specifiers, you must instead call `gprintf()`.
+ For information on sprintf format specifiers, please see standard C-language
+ documentation or the unix sprintf man page.
+4 strlen
+?expressions functions strlen
+?functions strlen
+?strlen
+#strlen("string") & string & int length of string \\
+%strlen("string")@string@int length of string
+ `strlen("string")` returns the number of characters in the string.
+4 strstrt
+?expressions functions strstrt
+?functions strstrt
+?strstrt
+#strstrt("string","key") & strings & int index of first character of substring "key" \\
+%strstrt("string","key")@strings@int index of first character of substring "key"
+ `strstrt("string","key")` searches for the character string "key" in "string"
+ and returns the index to the first character of "key". If "key" is not found,
+ returns 0. Similar to C library function strstr except that it returns an
+ index rather than a string pointer. strstrt("hayneedlestack","needle") = 4.
+4 substr
+?expressions functions substr
+?functions substr
+?substr
+=substring
+#substr("string",beg,end) & multiple & string "string"[beg:end] \\
+%substr("string",beg,end)@multiple@string "string"[beg:end]
+ `substr("string",beg,end)` returns the substring consisting of characters
+ beg through end of the original string. This is exactly equivalent to the
+ expression "string"[beg:end] except that you do not have the option of
+ ommitting beg or end.
+4 strftime
+?expressions functions strftime
+?functions strftime
+?strftime
+#strftime("timeformat",t) & any & string result from applying gnuplot's time parser \\
+%strftime("timeformat",t)@any@string result from applying gnuplot's time parser
+ `strftime("timeformat",t)` applies the timeformat specifiers to the time t
+ given in seconds since the year 2000.
+ See `time_specifiers` and `strptime`.
+4 strptime
+? expressions functions strptime
+?functions strptime
+?strptime
+#strptime("timeformat",s) & string & seconds since year 2000 as given in string s \\
+%strptime("timeformat",s)@string@seconds since year 2000 as given in string s
+ `strptime("timeformat",s)` reads the time from the string s using the
+ timeformat specifiers and converts it into seconds since the year 2000.
+ See `time_specifiers` and `strftime`.
+4 system
+?expressions functions system
+?functions system
+?system function
+=system
+#system("command") & string & string containing output stream of shell command \\
+%system("command")@string@stdout containing output stream of shell command
+ `system("command")` executes "command" using the standard shell and returns
+ the resulting character stream from stdout as string variable.
+ One optional trailing newline is ignored.
+
+ This can be used to import external functions into gnuplot scripts using
+ 'f(x) = real(system(sprintf("somecommand %f", x)))'.
+4 word
+?expressions functions word
+?functions word
+?word
+=word
+#word("string",n) & string, int & returns the nth word in "string" \\
+%word("string",n)@string, int@returns the nth word in "string"
+ `word("string",n)` returns the nth word in string. For example,
+ `word("one two three",2)` returns the string "two".
+4 words
+?expressions functions words
+?functions words
+?words
+=words
+#words("string") & string & returns the number of words in "string" \\
+%words("string")@string@returns the number of words in "string"
+ `words("string")` returns the number of words in string. For example,
+ `words(" a b c d")` returns the 4.
+@end table
+
+@start table
+#\begin{tabular}{|ccl|} \hline
+#\multicolumn{3}{|c|}{other {\bf gnuplot} functions} \\ \hline \hline
+#Function & Arguments & Returns \\ \hline
+%c c l .
+%Function@Arguments@Returns
+%_
+4 column
+?expressions functions column
+?functions column
+?column
+#column(x) & int & column $x$ during datafile manipulation. \\
+%column(x)@int@ column $x$ during datafile manipulation.
+ `column(x)` may be used only in expressions as part of `using` manipulations
+ to fits or datafile plots. It evaluates to the numerical value of the contents
+ of column x. See `plot datafile using`.
+4 defined
+?expressions functions defined
+?functions defined
+?defined
+#defined(X) & variable name & [DEPRECATED] returns 1 if X is defined, 0 otherwise. \\
+%defined(X)@variable name@ [DEPRECATED] returns 1 if X is defined, 0 otherwise.
+ `defined(X)` [DEPRECATED] returns 1 if a variable named X has been defined, otherwise
+ it returns 0.
+4 exists
+?expressions functions exists
+?functions exists
+?exists
+#exists("X") & "variable name" & returns 1 if a variable named X is defined, 0 otherwise. \\
+%exists("X")@"variable name"@ returns 1 if a variable named X is defined, 0 otherwise.
+ The argument to exists() is a string constant or a string variable;
+ if the string contains the name of a defined variable, the function returns 1.
+ Otherwise the function returns 0.
+4 stringcolumn
+?expressions functions stringcolumn
+?functions stringcolumn
+?stringcolumn
+?expressions functions strcol
+?functions strcol
+?strcol
+#stringcolumn(x) & int & content of column $x$ as a string. \\
+%stringcolumn(x)@int@ content column $x$ as a string.
+ `stringcolumn(x)` may be used only in expressions as part of `using` manipulations
+ to fits or datafile plots. It returns the content of column x as a string variable.
+ See `plot datafile using`.
+4 timecolumn
+?expressions functions timecolumn
+?functions timecolumn
+?timecolumn
+#timecolumn(x) & int & timecolumn $x$ during datafile manipulation. \\
+%timecolumn(x)@int@ timecolumn $x$ during datafile manipulation.
+ `timecolumn(x)` may be used only in expressions as part of `using`
+ manipulations to fits or datafile plots. See `plot datafile using`.
+
+ It reads the data starting at that column as a time/date value and
+ returns its value in gnuplot's internal time representation of
+ "seconds since the millennium".
+
+ To find the right `timefmt` string to use, `timecolumn` searches for a
+ `using` specification with the same column number as its argument.
+ If one is found, `timefmt` pattern of the target axis for this specifier
+ is used. Otherwise, `timecolumn` chooses the x axis `timefmt` per default.
+4 tm_hour
+?expressions tm_hour
+?functions tm_hour
+?tm_hour
+#tm\_hour(x) & int & the hour \\
+%tm_hour(x)@int@the hour
+ The `tm_hour` function interprets its argument as a time, in seconds from
+ 1 Jan 2000. It returns the hour (an integer in the range 0--23) as a real.
+4 tm_mday
+?expressions tm_mday
+?functions tm_mday
+?tm_mday
+#tm\_mday(x) & int & the day of the month \\
+%tm_mday(x)@int@the day of the month
+ The `tm_mday` function interprets its argument as a time, in seconds from
+ 1 Jan 2000. It returns the day of the month (an integer in the range 1--31)
+ as a real.
+4 tm_min
+?expressions tm_min
+?functions tm_min
+?tm_min
+#tm\_min(x) & int & the minute \\
+%tm_min(x)@int@the minute
+ The `tm_min` function interprets its argument as a time, in seconds from
+ 1 Jan 2000. It returns the minute (an integer in the range 0--59) as a real.
+4 tm_mon
+?expressions tm_mon
+?functions tm_mon
+?tm_mon
+#tm\_mon(x) & int & the month \\
+%tm_mon(x)@int@the month
+ The `tm_mon` function interprets its argument as a time, in seconds from
+ 1 Jan 2000. It returns the month (an integer in the range 0--11) as a real.
+4 tm_sec
+?expressions tm_sec
+?functions tm_sec
+?tm_sec
+#tm\_sec(x) & int & the second \\
+%tm_sec(x)@int@the second
+ The `tm_sec` function interprets its argument as a time, in seconds from
+ 1 Jan 2000. It returns the second (an integer in the range 0--59) as a real.
+4 tm_wday
+?expressions tm_wday
+?functions tm_wday
+?tm_wday
+#tm\_wday(x) & int & the day of the week \\
+%tm_wday(x)@int@the day of the week
+ The `tm_wday` function interprets its argument as a time, in seconds from
+ 1 Jan 2000. It returns the day of the week (an integer in the range 0--6) as
+ a real.
+4 tm_yday
+?expressions tm_yday
+?functions tm_yday
+?tm_yday
+#tm\_yday(x) & int & the day of the year \\
+%tm_yday(x)@int@the day of the year
+ The `tm_yday` function interprets its argument as a time, in seconds from
+ 1 Jan 2000. It returns the day of the year (an integer in the range 1--366)
+ as a real.
+4 tm_year
+?expressions tm_year
+?functions tm_year
+?tm_year
+#tm\_year(x) & int & the year \\
+%tm_year(x)@int@the year
+ The `tm_year` function interprets its argument as a time, in seconds from
+ 1 Jan 2000. It returns the year (an integer) as a real.
+4 valid
+?expressions functions valid
+?functions valid
+?valid
+#valid(x) & int & test validity of $\mbox{column}(x)$ during datafile manip.\\
+%valid(x)@int@ test validity of column($x$) during datafile manip.
+ `valid(x)` may be used only in expressions as part of `using` manipulations
+ to fits or datafile plots. See `plot datafile using`.
+@end table
+ See also
+^ <a href="http://www.gnuplot.info/demo/airfoil.html">
+ airfoil.dem: use of functions and complex variables for airfoils demo.
+^ </a>
+
+4 Random number generator
+?expressions random
+?functions random
+?random
+ The behavior of the built-in function `rand(x)` has changed as of version 3.8l.
+ Older scripts that expected rand(x>0) to produce sequential pseudo-random
+ numbers from the same seeded sequence must be changed to call rand(0) instead.
+ The current behavior is as follows:
+ `rand(0)` returns a pseudo random number in the interval [0:1] generated
+ from the current value of two internal 32-bit seeds.
+ `rand(-1)` resets both seeds to a standard value.
+ `rand(x)` for x>0 sets both seeds to a value based on the value of x.
+ `rand({x,y})` for x>0 sets seed1 to x and seed2 to y.
+
+3 Operators
+?expressions operators
+?operators
+ The operators in `gnuplot` are the same as the corresponding operators in the
+ C programming language, except that all operators accept integer, real, and
+ complex arguments, unless otherwise noted. The ** operator (exponentiation)
+ is supported, as in FORTRAN.
+
+ Parentheses may be used to change order of evaluation.
+4 Unary
+?expressions operators unary
+?operators unary
+?unary
+ The following is a list of all the unary operators and their usages:
+
+@start table - first is interactive cleartext form
+ Symbol Example Explanation
+ - -a unary minus
+ + +a unary plus (no-operation)
+ ~ ~a * one's complement
+ ! !a * logical negation
+ ! a! * factorial
+ $ $3 * call arg/column during `using` manipulation
+=factorial
+=negation
+=one's complement
+=operator precedence
+#\begin{tabular}{|ccl|} \hline
+#\multicolumn{3}{|c|}{Unary Operators}\\ \hline \hline
+#Symbol & Example & Explanation \\ \hline
+#\verb@-@ & \verb@-a@ & unary minus \\
+#\verb@+@ & \verb@+a@ & unary plus (no-operation) \\
+#\verb@~@ & \verb@~a@ & * one's complement \\
+#\verb@!@ & \verb@!a@ & * logical negation \\
+#\verb@!@ & \verb@a!@ & * factorial \\
+#\verb@$@ & \verb@$3@ & * call arg/column during `using` manipulation \\
+C ugly hack: doc2ms uses $ as delimiter for eqn's so it doesn't seem to
+C be able to print them. So we have to typeset this table without using
+C eqn (at least that's the only solution I found, without any real docs
+C on *roff and eqn
+C First, terminate the table doc2ms.c already started:
+%.TE
+C ... then turn off eqn delimiters:
+%.EQ
+%delim off
+%.EN
+C ... and restart the table:
+%.TS
+%center box tab (@) ;
+%c c l .
+%Symbol@Example@Explanation
+%_
+%-@-a@unary minus
+%+@+a@unary plus (no-operation)
+%~@~a@* one's complement
+%!@!a@* logical negation
+%!@a!@* factorial
+%$@$3@* call arg/column during `using` manipulation
+%_
+@end table
+ (*) Starred explanations indicate that the operator requires an integer
+ argument.
+
+ Operator precedence is the same as in Fortran and C. As in those languages,
+ parentheses may be used to change the order of operation. Thus -2**2 = -4,
+ but (-2)**2 = 4.
+
+ The factorial operator returns a real number to allow a greater range.
+4 Binary
+?expressions operators binary
+?operators binary
+ The following is a list of all the binary operators and their usages:
+
+@start table - first is interactive cleartext form
+ Symbol Example Explanation
+ ** a**b exponentiation
+ * a*b multiplication
+ / a/b division
+ % a%b * modulo
+ + a+b addition
+ - a-b subtraction
+ == a==b equality
+ != a!=b inequality
+ < a<b less than
+ <= a<=b less than or equal to
+ > a>b greater than
+ >= a>=b greater than or equal to
+ & a&b * bitwise AND
+ ^ a^b * bitwise exclusive OR
+ | a|b * bitwise inclusive OR
+ && a&&b * logical AND
+ || a||b * logical OR
+ . A.B string concatenation
+ eq A eq B string equality
+ ne A ne B string inequality
+=bitwise operators
+=string operators
+=modulo
+=exponentiation
+#\begin{tabular}{|ccl|} \hline
+#\multicolumn{3}{|c|}{Binary Operators} \\ \hline \hline
+#Symbol & Example & Explanation \\ \hline
+#\verb~**~ & \verb~a**b~ & exponentiation\\
+#\verb~*~ & \verb~a*b~ & multiplication\\
+#\verb~/~ & \verb~a/b~ & division\\
+#\verb~%~ & \verb~a%b~ & * modulo\\
+#\verb~+~ & \verb~a+b~ & addition\\
+#\verb~-~ & \verb~a-b~ & subtraction\\
+#\verb~==~ & \verb~a==b~ & equality\\
+#\verb~!=~ & \verb~a!=b~ & inequality\\
+#\verb~<~ & \verb~a<b~ & less than\\
+#\verb~<=~ & \verb~a<=b~ & less than or equal to\\
+#\verb~>~ & \verb~a>b~ & greater than\\
+#\verb~>=~ & \verb~a>=b~ & greater than or equal to\\
+#\verb~&~ & \verb~a&b~ & * bitwise AND\\
+#\verb~^~ & \verb~a^b~ & * bitwise exclusive OR\\
+#\verb~|~ & \verb~a|b~ & * bitwise inclusive OR\\
+#\verb~&&~ & \verb~a&&b~ & * logical AND\\
+#\verb~||~ & \verb~a||b~ & * logical OR\\
+#\verb~.~ & \verb~A.B~ & string concatenation\\
+#\verb~eq~ & \verb~A eq B~ & string equality\\
+#\verb~ne~ & \verb~A ne B~ & string inequality\\
+%c c l .
+%Symbol@Example@Explanation
+%_
+%**@a**b@exponentiation
+%*@a*b@multiplication
+%/@a/b@division
+%%@a%b@* modulo
+%+@a+b@addition
+%-@a-b@subtraction
+%==@a==b@equality
+%!=@a!=b@inequality
+%<@a<b@less than
+%<=@a<=b@less than or equal to
+%>@a>b@greater than
+%>=@a>=b@greater than or equal to
+%&@a&b@* bitwise AND
+%^@a^b@* bitwise exclusive OR
+%|@a|b@* bitwise inclusive OR
+%&&@a&&b@* logical AND
+%||@a||b@* logical OR
+%.@a.b@string concatenation
+%eq@A eq B@string equality
+%ne@A ne B@string inequality
+
+@end table
+ (*) Starred explanations indicate that the operator requires integer
+ arguments.
+ Capital letters A and B indicate that the operator requires string arguments.
+
+ Logical AND (&&) and OR (||) short-circuit the way they do in C. That is,
+ the second `&&` operand is not evaluated if the first is false; the second
+ `||` operand is not evaluated if the first is true.
+4 Ternary
+?expressions operators ternary
+?operators ternary
+?ternary
+ There is a single ternary operator:
+
+@start table - first is interactive cleartext form
+ Symbol Example Explanation
+ ?: a?b:c ternary operation
+#\begin{tabular}{|ccl|} \hline
+#\multicolumn{3}{|c|}{Ternary Operator} \\ \hline \hline
+#Symbol & Example & Explanation \\ \hline
+#\verb~?:~ & \verb~a?b:c~ & ternary operation\\
+%c c l .
+%Symbol@Example@Explanation
+%_
+%?:@a?b:c@* ternary operation
+
+@end table
+ The ternary operator behaves as it does in C. The first argument (a), which
+ must be an integer, is evaluated. If it is true (non-zero), the second
+ argument (b) is evaluated and returned; otherwise the third argument (c) is
+ evaluated and returned.
+
+ The ternary operator is very useful both in constructing piecewise functions
+ and in plotting points only when certain conditions are met.
+
+ Examples:
+
+ Plot a function that is to equal sin(x) for 0 <= x < 1, 1/x for 1 <= x < 2,
+ and undefined elsewhere:
+ f(x) = 0<=x && x<1 ? sin(x) : 1<=x && x<2 ? 1/x : 1/0
+ plot f(x)
+^ <img align=bottom src="http://www.gnuplot.info/doc/ternary.gif" alt="[ternary.gif]" width=640 height=480>
+ Note that `gnuplot` quietly ignores undefined values, so the final branch of
+ the function (1/0) will produce no plottable points. Note also that f(x)
+ will be plotted as a continuous function across the discontinuity if a line
+ style is used. To plot it discontinuously, create separate functions for the
+ two pieces. (Parametric functions are also useful for this purpose.)
+
+ For data in a file, plot the average of the data in columns 2 and 3 against
+ the datum in column 1, but only if the datum in column 4 is non-negative:
+
+ plot 'file' using 1:( $4<0 ? 1/0 : ($2+$3)/2 )
+
+ Please see `plot datafile using` for an explanation of the `using` syntax.
+
+3 Gnuplot-defined variables
+?gnuplot-defined variables
+ The variable `pi` is defined to be pi, see
+ print pi
+
+ Additionally, gnuplot may define some variables under various operations.
+
+ Working with interactive terminals with `mouse` functionality defines
+ variables with names that begin "MOUSE_", see `mouse variables` for details.
+
+ Further, there are several "read-only" variables that begin "GPVAL_", like
+ GPVAL_TERM, GPVAL_X_MIN, GPVAL_X_MAX, GPVAL_Y_MIN,... Type `show variables all`
+ to display their list and values. Values related to axes parameters (ranges, log
+ base) are values used during the last plot, not those currently `set`.
+
+ The `fit` mechanism uses several variables with names that begin "FIT_". It
+ is safest to avoid using such names. "FIT_LIMIT", however, is one that you
+ may wish to redefine. Under `set fit errorvariables`, the error for each
+ fitted parameter will be stored in a variable named like the parameter, but
+ with "_err" appended. See the documentation on `fit` for details.
+
+ See `user-defined variables`, `mouse variables`, and `fit`.
+
+3 User-defined variables and functions
+?expressions user-defined
+?user-defined variables
+?user-defined
+?variables
+ New user-defined variables and functions of one through five variables may
+ be declared and used anywhere, including on the `plot` command itself.
+
+ User-defined function syntax:
+ <func-name>( <dummy1> {,<dummy2>} ... {,<dummy5>} ) = <expression>
+
+ where <expression> is defined in terms of <dummy1> through <dummy5>.
+
+ User-defined variable syntax:
+ <variable-name> = <constant-expression>
+
+ Examples:
+ w = 2
+ q = floor(tan(pi/2 - 0.1))
+ f(x) = sin(w*x)
+ sinc(x) = sin(pi*x)/(pi*x)
+ delta(t) = (t == 0)
+ ramp(t) = (t > 0) ? t : 0
+ min(a,b) = (a < b) ? a : b
+ comb(n,k) = n!/(k!*(n-k)!)
+ len3d(x,y,z) = sqrt(x*x+y*y+z*z)
+ plot f(x) = sin(x*a), a = 0.2, f(x), a = 0.4, f(x)
+
+ file = "mydata.inp"
+ file(n) = sprintf("run_%d.dat",n)
+
+^ <img align=bottom src="http://www.gnuplot.info/doc/userdefined.gif" alt="[userdefined.gif]" width=640 height=480>
+ The final two examples illustrate a user-defined string variable and a
+ user-defined string function.
+
+=NaN
+=pi
+ Note that the variables `pi` (3.14159...) and `NaN` (IEEE "Not a Number") are
+ already defined. You can redefine these to something else if you really need
+ to. The original values can be recovered by setting:
+
+ NaN = GPVAL_NaN
+ pi = GPVAL_pi
+
+ Other variables may be defined under various gnuplot operations like mousing in
+ interactive terminals or fitting; see `gnuplot-defined variables` for details.
+
+ You can check for existence of a given variable V by the exists("V")
+ expression. For example
+ a = 10
+ if (exists("a")) print "a is defined"
+ if (!exists("b")) print "b is not defined"
+
+ Valid names are the same as in most programming languages: they must begin
+ with a letter, but subsequent characters may be letters, digits, "$", or "_".
+
+ See `show functions`, `functions`, `gnuplot-defined variables`, `macros`.
+2 Glossary
+?glossary
+ Throughout this document an attempt has been made to maintain consistency of
+ nomenclature. This cannot be wholly successful because as `gnuplot` has
+ evolved over time, certain command and keyword names have been adopted that
+ preclude such perfection. This section contains explanations of the way
+ some of these terms are used.
+
+ A "page" or "screen" is the entire area addressable by `gnuplot`. On a
+ monitor, it is the full screen; on a plotter, it is a single sheet of paper.
+
+ A screen may contain one or more "plots". A plot is defined by an abscissa
+ and an ordinate, although these need not actually appear on it, as well as
+ the margins and any text written therein.
+
+ A plot contains one "graph". A graph is defined by an abscissa and an
+ ordinate, although these need not actually appear on it.
+
+ A graph may contain one or more "lines". A line is a single function or
+ data set. "Line" is also a plotting style. The word will also be used in
+ sense "a line of text". Presumably the context will remove any ambiguity.
+
+ The lines on a graph may have individual names. These may be listed
+ together with a sample of the plotting style used to represent them in
+ the "key", sometimes also called the "legend".
+
+ The word "title" occurs with multiple meanings in `gnuplot`. In this
+ document, it will always be preceded by the adjective "plot", "line", or
+ "key" to differentiate among them.
+
+ A 2-d graph may have up to four labelled axes. The names of the four axes
+ for these usages are "x" for the axis along the bottom border of the plot,
+ "y" for the left border, "x2" for the top border, and "y2" for the right
+ border.
+
+ A 3-d graph may have up to three labelled axes -- "x", "y" and "z". It is
+ not possible to say where on the graph any particular axis will fall because
+ you can change the direction from which the graph is seen with `set view`.
+
+ When discussing data files, the term "record" will be resurrected and used
+ to denote a single line of text in the file, that is, the characters between
+ newline or end-of-record characters. A "point" is the datum extracted from
+ a single record. A "datablock" is a set of points from consecutive records,
+ delimited by blank records. A line, when referred to in the context of a
+ data file, is a subset of a datablock.
+2 linetype, colors, and styles
+?linetype
+?colors
+ Each gnuplot terminal type provides a set of distinct "linetypes". These may
+ differ in color, in thickness, in dot/dash pattern, or in some combination of
+ color and dot/dash. The default linetypes for a particular terminal can be
+ previewed by issuing the `test` command after setting the terminal type.
+ The pre-defined colors and dot/dash patterns are not guaranteed to be
+ consistent for all terminal types, but all terminals use the special linetype
+ -1 to mean a solid line in the primary foreground color (normally black).
+ By default, successive functions or datafiles plotted by a single command will
+ be assigned successive linetypes. You can override this default by specifying
+ a particular linetype for any function, datafile, or plot element.
+
+ Examples:
+
+ plot "foo", "bar" # plot two files using linetypes 1, 2
+ plot sin(x) linetype 4 # terminal-specific linetype color 4
+ plot sin(x) lt -1 # black
+
+=colors
+ For many terminal types it is also possible to assign user-defined colors
+ using explicit rgb (red, green, blue) values, named colors, or color values
+ that refer to the current PM3D palette.
+
+ Examples:
+
+ plot sin(x) lt rgb "violet" # one of gnuplot's named colors
+ plot sin(x) lt rgb "#FF00FF" # explicit RGB triple in hexadecimal
+ plot sin(x) lt palette cb -45 # whatever color corresponds to -45
+ # in the current cbrange of the palette
+ plot sin(x) lt palette frac 0.3 # fractional value along the palette
+
+ See `show palette colornames`, `set palette`, `cbrange`.
+
+ For terminals that support dot/dash patterns, each default linetype has both
+ a dot-dash pattern and a default color. However, you can override the default
+ color by using the keyword `linecolor`, abbreviated `lc`. For example, the
+ postscript terminal provides a dashed blue line as linetype 3. The plot
+ commands below use this same dash pattern for three plots, one in blue (the
+ default), another in red (the default for linetype 1), and a third in gold.
+
+ Example:
+
+ set term postscript dashed color
+ plot 'foo' lt 3, 'baz' lt 3 linecolor 1, 'bar' lt 3 lc rgb 'gold'
+
+ Lines can have additional properties such as linewidth. You can associate
+ these various properties, as well as equivalent properties for point symbols,
+ into user-defined "line styles" using the command `set style line`. Once
+ you have defined a linestyle, you can use it in a plot command to control
+ the appearance of one or more plot elements.
+
+ Examples:
+
+ # define a new line style with terminal-independent color cyan,
+ # linewidth 3, and associated point type 6 (a circle with a dot in it).
+ set style line 5 lt rgb "cyan" lw 3 pt 6
+ plot sin(x) with linespoints ls 5 # user-defined line style 5
+
+ See `linestyle`, `set style line`.
+3 colorspec
+?colorspec
+?rgbcolor
+?lc
+?linecolor
+?tc
+?textcolor
+=colors
+ Many commands allow you to specify a linetype with an explicit color.
+ Note that not all terminals support RGB colors or pm3d palette colors.
+
+ Syntax:
+
+ ... {linetype | lt} <colorspec>
+ ... {linecolor | lc} <colorspec>
+ ... {textcolor | tc} <colorspec>
+
+ where <colorspec> has one of the following forms:
+
+ rgbcolor "colorname"
+ rgbcolor "#RRGGBB"
+ rgbcolor variable
+ palette frac <val> # <val> runs from 0 to 1
+ palette cb <value> # <val> lies within cbrange
+ palette z
+ variable # color index is read from input file
+
+ "colorname" refers to one of the color names built in to gnuplot. For a list
+ of the available names, see `show palette colornames`.
+
+ "#RRGGBB" is a hexadecimal constant preceded by the "#" symbol. The RRGGBB
+ represents the red, green, and blue components of the color, each on a scale
+ from 0 - 255. For example, magenta = full-scale red + full-scale blue would
+ be represented by #FF00FF, which is the hexadecimal representation of
+ (255 << 16) + (0 << 8) + (255).
+
+ "rgb variable" requires an additional column in the `using` specifier, and
+ is only available in 3D plotting mode (splot). The extra column is interpreted
+ as a 24-bit packed RGB triple. These are most easily specified in a data file
+ as hexadecimal values (see above).
+
+ Example:
+
+ rgb(r,g,b) = 65536 * int(r) + 256 * int(g) + int(b)
+ splot "data" using 1:2:3:(rgb($1,$2,$3)) with points lc rgb variable
+
+ The color palette is a linear gradient of colors that smoothly maps a
+ single numerical value onto a particular color. Two such mappings are always
+ in effect. `palette frac` maps a fractional value between 0 and 1 onto the
+ full range of the color palette. `palette cb` maps the range of the color
+ axis onto the same palette. See `set cbrange`. See also `set colorbox`.
+ You can use either of these to select a constant color from the current
+ palette.
+
+ "palette z" maps the z value of each plot segment or plot element into the
+ cbrange mapping of the palette. This allows smoothly-varying color along a
+ 3D line or surface. It also allows coloring 2D plots by palette values read
+ from an extra column of data.
+4 linecolor variable
+?linecolor variable
+?lc variable
+?textcolor variable
+?tc variable
+ Most plot commands assign a single color (linetype) to each element of the
+ plot. If there are multiple plots on a single graph, the default color
+ (linetype) is incremented sequentially. You can instead assign a separate
+ color for each data point, line segment, or label based on additional
+ information in the input data file. This is indicated by the colorspec
+ keyword `variable`.
+
+ `lc variable` tells the program to use the value read from one column of the
+ input data as a linestyle index, and use the color belonging to that linestyle.
+ This requires a corresponding additional column in the `using` specifier.
+ Text colors can be set similarly using `tc variable`.
+
+ A single data file may contain multiple sets of data, separated by two blank
+ lines. Each of these separate sets is assigned an index value (see `index`)
+ that can be retrieved via the using specifier column(-2).
+ All data in the file is drawn with the same color/linestyle/pointtype
+ properties by default. The command `lc variable` can be used to assign
+ different colors to each data set in the file by using the index value from
+ pseudocolumn -2.
+
+ Examples:
+ # Use the third column of data to assign colors to individual points
+ plot 'data' using 1:2:3 with points lc variable
+
+ # Use the data set index to choose a linestyle color
+ plot 'data' using 1:2:(column(-2)) with lines lc variable
+
+2 mouse input
+?mouse input
+ The `x11`, `pm`, `windows`, `ggi`, and `wxt` terminals allow interaction with
+ the current plot using the mouse. They also support the definition of hotkeys
+ to activate pre-defined functions by hitting a single key while the mouse
+ focus is in the active plot window. It is even possible to combine mouse
+ input with `batch` command scripts, by invoking the command `pause mouse`
+ and then using the mouse variables returned by mouse clicking as parameters
+ for subsequent scripted actions. See `bind` and `mouse variables`.
+ See also the command `set mouse`.
+3 bind
+?commands bind
+?bind
+ The `bind` allows defining or redefining a hotkey, i.e. a sequence of gnuplot
+ commands which will be executed when a certain key or key sequence is pressed
+ while the driver's window has the input focus. Note that `bind` is only
+ available if gnuplot was compiled with `mouse` support and it is used by all
+ mouse-capable terminals. Bindings overwrite the builtin bindings (like in
+ every real editor), except <space> and 'q' which cannot be rebound (unless
+ one exception, see below). Mouse buttons cannot be rebound.
+
+ You get the list of all hotkeys by typing `bind` or by hitting 'h' in the
+ graph window.
+
+ Note that multikey-bindings with modifiers have to be quoted.
+
+ Normally hotkeys are only recognized when the currently active plot window
+ has focus. `bind allwindows <key> ...` (short form: `bind all <key> ...`)
+ causes the binding for <key> to apply to all gnuplot plot windows, active
+ or not. In this case gnuplot variable MOUSE_KEY_WINDOW is set to the ID
+ of the originating window, and may be used by the bound command.
+
+ By default, the <space> hotkey raises gnuplot's command window. On some
+ terminals (e.g. x11, wx), 'q' closes the graph window. These defaults can
+ be changed to ctrl-space and ctrl-q by starting gnuplot as 'gnuplot -ctrlq',
+ see `x11 command-line-options`, or by the X Resource 'gnuplot*ctrlq'.
+ Note: if <space> (or ctrl-space) does not raise the gnuplot window under X11,
+ see discussion in `raise`.
+
+ Syntax:
+ bind {allwindows} [<key-sequence>] ["<gnuplot commands>"]
+ bind!
+
+ Examples:
+
+ - set bindings:
+
+ bind a "replot"
+ bind "ctrl-a" "plot x*x"
+ bind "ctrl-alt-a" 'print "great"'
+ bind Home "set view 60,30; replot"
+ bind all Home 'print "This is window ",MOUSE_KEY_WINDOW'
+
+ - show bindings:
+ bind "ctrl-a" # shows the binding for ctrl-a
+ bind # shows all bindings
+
+ - remove bindings:
+ bind "ctrl-alt-a" "" # removes binding for ctrl-alt-a
+ (note that builtins cannot be removed)
+ bind! # installs default (builtin) bindings
+
+ - bind a key to toggle something:
+ v=0
+ bind "ctrl-r" "v=v+1;if(v%2)set term x11 noraise; else set term x11 raise"
+
+ Modifiers (ctrl / alt) are case insensitive, keys not:
+ ctrl-alt-a == CtRl-alT-a
+ ctrl-alt-a != ctrl-alt-A
+
+ List of modifiers (alt == meta):
+ ctrl, alt
+
+ List of supported special keys:
+
+ "BackSpace", "Tab", "Linefeed", "Clear", "Return", "Pause", "Scroll_Lock",
+ "Sys_Req", "Escape", "Delete", "Home", "Left", "Up", "Right", "Down",
+ "PageUp", "PageDown", "End", "Begin",
+
+ "KP_Space", "KP_Tab", "KP_Enter", "KP_F1", "KP_F2", "KP_F3", "KP_F4",
+ "KP_Home", "KP_Left", "KP_Up", "KP_Right", "KP_Down", "KP_PageUp",
+ "KP_PageDown", "KP_End", "KP_Begin", "KP_Insert", "KP_Delete", "KP_Equal",
+ "KP_Multiply", "KP_Add", "KP_Separator", "KP_Subtract", "KP_Decimal",
+ "KP_Divide",
+
+ "KP_1" - "KP_9", "F1" - "F12"
+
+ See also help for `mouse` and `if`.
+
+3 Mouse variables
+?mouse variables
+ When mousing is active, clicking in the active window will set several user
+ variables that can be accessed from the gnuplot command line. The coordinates
+ of the mouse at the time of the click are stored in MOUSE_X MOUSE_Y MOUSE_X2
+ and MOUSE_Y2. The mouse button clicked, and any meta-keys active at that time,
+ are stored in MOUSE_BUTTON MOUSE_SHIFT MOUSE_ALT and MOUSE_CTRL. These
+ variables are set to undefined at the start of every plot, and only become
+ defined in the event of a mouse click in the active plot window. To determine
+ from a script if the mouse has been clicked in the active plot window, it is
+ sufficient to test for any one of these variables being defined.
+
+ plot 'something'
+ pause mouse
+ if (defined(MOUSE_BUTTON)) call 'something_else'; \
+ else print "No mouse click."
+
+ It is also possible to track keystrokes in the plot window using the mousing
+ code.
+
+ plot 'something'
+ pause mouse keypress
+ print "Keystroke ", MOUSE_KEY, " at ", MOUSE_X, " ", MOUSE_Y
+
+ When `pause mouse keypress` is terminated by a keypress, then MOUSE_KEY will
+ contain the ascii character value of the key that was pressed. MOUSE_CHAR will
+ contain the character itself as a string variable. If the pause command is
+ terminated abnormally (e.g. by ctrl-C or by externally closing the plot window)
+ then MOUSE_KEY will equal -1.
+
+ Note that after a zoom by mouse, you can read the new ranges as GPVAL_X_MIN,
+ GPVAL_X_MAX, GPVAL_Y_MIN, and GPVAL_Y_MAX, see `gnuplot-defined variables`.
+
+
+2 Plotting
+?plotting
+ There are three `gnuplot` commands which actually create a plot: `plot`,
+ `splot` and `replot`. `plot` generates 2-d plots, `splot` generates 3-d
+ plots (actually 2-d projections, of course), and `replot` appends its
+ arguments to the previous `plot` or `splot` and executes the modified
+ command.
+
+ Much of the general information about plotting can be found in the discussion
+ of `plot`; information specific to 3-d can be found in the `splot` section.
+
+ `plot` operates in either rectangular or polar coordinates -- see `set polar`
+ for details of the latter. `splot` operates only in rectangular coordinates,
+ but the `set mapping` command allows for a few other coordinate systems to be
+ treated. In addition, the `using` option allows both `plot` and `splot` to
+ treat almost any coordinate system you'd care to define.
+
+ `plot` also lets you use each of the four borders -- x (bottom), x2 (top), y
+ (left) and y2 (right) -- as an independent axis. The `axes` option lets you
+ choose which pair of axes a given function or data set is plotted against. A
+ full complement of `set` commands exists to give you complete control over
+ the scales and labelling of each axis. Some commands have the name of an
+ axis built into their names, such as `set xlabel`. Other commands have one
+ or more axis names as options, such as `set logscale xy`. Commands and
+ options controlling the z axis have no effect on 2-d graphs.
+
+ `splot` can plot surfaces and contours in addition to points and/or lines.
+ In addition to `splot`, see `set isosamples` for information about defining
+ the grid for a 3-d function; `splot datafile` for information about the
+ requisite file structure for 3-d data values; and `set contour` and
+ `set cntrparam` for information about contours.
+
+ In `splot`, control over the scales and labels of the axes are the same as
+ with `plot`, except that commands and options controlling the x2 and y2 axes
+ have no effect whereas of course those controlling the z axis do take effect.
+2 Start-up
+^ <a name="start-up"></a>
+?startup
+?start
+?.gnuplot
+ When `gnuplot` is run, it looks for an initialization file to load.
+ This file is called `.gnuplot` on Unix and AmigaOS systems, and
+ `GNUPLOT.INI` on other systems. If this file is not found in the
+ current directory, the program will look for it in the HOME directory
+ (under AmigaOS, Atari(single)TOS, MS-DOS, Windows and OS/2, the
+ environment variable `GNUPLOT` should contain the name of this
+ directory; on Windows NT, it will use `USERPROFILE` if GNUPLOT isn't
+ defined). Note: if NOCWDRC is defined during the installation,
+ `gnuplot` will not read from the current directory.
+
+ If the initialization file is found, `gnuplot` executes the commands in it.
+ These may be any legal `gnuplot` commands, but typically they are limited to
+ setting the terminal and defining frequently-used functions or variables.
+2 String constants and string variables
+?strings
+?string variables
+ In addition to string constants, most gnuplot commands also accept a string
+ variable, a string expression, or a function that returns a string.
+ For example, the following four methods of creating a plot all result in the
+ same plot title:
+
+ four = "4"
+ graph4 = "Title for plot #4"
+ graph(n) = sprintf("Title for plot #%d",n)
+
+ plot 'data.4' title "Title for plot #4"
+ plot 'data.4' title graph4
+ plot 'data.4' title "Title for plot #".four
+ plot 'data.4' title graph(4)
+
+ Since integers are promoted to strings when operated on by the string
+ concatenation operator, the following method also works:
+
+ N = 4
+ plot 'data.'.N title "Title for plot #".N
+
+ In general, elements on the command line will only be evaluated as possible
+ string variables if they are not otherwise recognizable as part of the normal
+ gnuplot syntax. So the following sequence of commands is legal, although
+ probably should be avoided so as not to cause confusion:
+
+ plot = "my_datafile.dat"
+ title = "My Title"
+ plot plot title title
+
+ There are three binary operators that require string operands: the string
+ concatenation operator ".", the string equality operator "eq" and the string
+ inequality operator "ne". The following example will print TRUE.
+
+ if ("A"."B" eq "AB") print "TRUE"
+
+ See also the two string formatting functions `gprintf` and `sprintf`.
+
+=substring
+ Substrings can be specified by appending a range specifier to any string,
+ string variable, or string-valued function. The range specifier has the
+ form [begin:end], where begin is the index of the first character of the
+ substring and end is the index of the last character of the substring.
+ The first character has index 1. The begin or end fields may be empty, or
+ contain '*', to indicate the true start or end of the original string.
+ E.g. str[:] and str[*:*] both describe the full string str.
+2 Substitution and Command line macros
+?substitution
+ When a command line to gnuplot is first read, i.e. before it is interpreted
+ or executed, two forms of lexical substitution are performed. These are
+ triggered by the presence of text in backquotes (ascii character 96) or
+ preceded by @ (ascii character 64).
+3 Substitution of system commands in backquotes
+?substitution backquotes
+?backquotes
+?system commands
+ Command-line substitution is specified by a system command enclosed in
+ backquotes. This command is spawned and the output it produces replaces
+ the backquoted text on the command line. Some implementations also support
+ pipes; see `plot datafile special-filenames`.
+
+ Command-line substitution can be used anywhere on the `gnuplot` command
+ line, except inside strings delimited by single quotes.
+
+ Example:
+
+ This will run the program `leastsq` and replace `leastsq` (including
+ backquotes) on the command line with its output:
+ f(x) = `leastsq`
+
+ or, in VMS
+ f(x) = `run leastsq`
+
+ These will generate labels with the current time and userid:
+ set label "generated on `date +%Y-%m-%d` by `whoami`" at 1,1
+ set timestamp "generated on %Y-%m-%d by `whoami`"
+3 Substitution of string variables as macros
+?substitution macros
+?macros
+=exists
+ Substitution of command line macros is disabled by default, but may be
+ enabled using the `set macros` command. If macro substitution is enabled,
+ the character @ is used to trigger substitution of the current value of a
+ string variable into the command line. The text in the string variable may
+ contain any number of lexical elements. This allows string variables to be
+ used as command line macros. Only string constants may be expanded using this
+ mechanism, not string-valued expressions.
+ For example:
+
+ set macros
+ style1 = "lines lt 4 lw 2"
+ style2 = "points lt 3 pt 5 ps 2"
+ range1 = "using 1:3"
+ range2 = "using 1:5"
+ plot "foo" @range1 with @style1, "bar" @range2 with @style2
+
+ The line containing @ symbols is expanded on input, so that by the time it is
+ executed the effect is identical to having typed in full
+
+ plot "foo" using 1:3 with lines lt 4 lw 2, \
+ "bar" using 1:5 with points lt 3 pt 5 ps 2
+
+ The function exists() may be useful in connection with macro evaluation.
+ The following example checks that C can safely be expanded as the name of
+ a user-defined variable:
+
+ C = "pi"
+ if (exists(C)) print C," = ", @C
+
+ Macro expansion does not occur inside either single or double quotes.
+ However macro expansion does occur inside backquotes.
+3 String variables, macros, and command line substitution
+?mixing_macros_backquotes
+?substitution mixing_macros_backquotes
+ The interaction of string variables, backquotes and macro substitution is
+ somewhat complicated. Backquotes do not block macro substitution, so
+
+ filename = "mydata.inp"
+ lines = ` wc --lines @filename | sed "s/ .*//" `
+
+ results in the number of lines in mydata.inp being stored in the integer
+ variable lines. And double quotes do not block backquote substitution, so
+
+ mycomputer = "`uname -n`"
+
+ results in the string returned by the system command `uname -n` being stored
+ in the string variable mycomputer.
+
+ However, macro substitution is not performed inside double quotes, so you
+ cannot define a system command as a macro and then use both macro and backquote
+ substitution at the same time.
+
+ machine_id = "uname -n"
+ mycomputer = "`@machine_id`" # doesn't work!!
+
+ This fails because the double quotes prevent @machine_id from being interpreted
+ as a macro. To store a system command as a macro and execute it later you must
+ instead include the backquotes as part of the macro itself. This is
+ accomplished by defining the macro as shown below. Notice that the sprintf
+ format nests all three types of quotes.
+
+ machine_id = sprintf('"`uname -n`"')
+ mycomputer = @machine_id
+2 Syntax
+?syntax
+?specify
+?punctuation
+ Version 4 of gnuplot is much less sensitive than earlier versions to the
+ order of keywords and suboptions. However, if you get error messages from
+ specifying options that you think should work, please try rearranging them
+ into the exact order listed by the documentation.
+
+ Options and any accompanying parameters are separated by spaces whereas lists
+ and coordinates are separated by commas. Ranges are separated by colons and
+ enclosed in brackets [], text and file names are enclosed in quotes, and a
+ few miscellaneous things are enclosed in parentheses. Braces {} are used for
+ a few special purposes.
+
+ Commas are used to separate coordinates on the `set` commands `arrow`,
+ `key`, and `label`; the list of variables being fitted (the list after the
+ `via` keyword on the `fit` command); lists of discrete contours or the loop
+ parameters which specify them on the `set cntrparam` command; the arguments
+ of the `set` commands `dgrid3d`, `dummy`, `isosamples`, `offsets`, `origin`,
+ `samples`, `size`, `time`, and `view`; lists of tics or the loop parameters
+ which specify them; the offsets for titles and axis labels; parametric
+ functions to be used to calculate the x, y, and z coordinates on the `plot`,
+ `replot` and `splot` commands; and the complete sets of keywords specifying
+ individual plots (data sets or functions) on the `plot`, `replot` and `splot`
+ commands.
+
+ Parentheses are used to delimit sets of explicit tics (as opposed to loop
+ parameters) and to indicate computations in the `using` filter of the `fit`,
+ `plot`, `replot` and `splot` commands.
+
+ (Parentheses and commas are also used as usual in function notation.)
+
+ Square brackets are used to delimit ranges given in `set`, `plot`
+ or `splot` commands.
+
+ Colons are used to separate extrema in `range` specifications (whether they
+ are given on `set`, `plot` or `splot` commands) and to separate entries in
+ the `using` filter of the `plot`, `replot`, `splot` and `fit` commands.
+
+ Semicolons are used to separate commands given on a single command line.
+
+ Braces are used in text to be specially processed by some terminals, like
+ `postscript`. They are also used to denote complex numbers: {3,2} = 3 + 2i.
+
+ At present you should not embed \n inside {} when using the PostScript
+ terminal in `enhanced text` mode.
+
+ The EEPIC, Imagen, Uniplex, LaTeX, and TPIC drivers allow a newline to be
+ specified by \\ in a single-quoted string or \\\\ in a double-quoted string.
+3 Quote Marks
+?quotes
+?syntax quotes
+ Gnuplot uses three forms of quote marks for delimiting text strings,
+ double-quote (ascii 34), single-quote (ascii 39), and backquote (ascii 96).
+
+ Filenames may be entered with either single- or double-quotes. In this
+ manual the command examples generally single-quote filenames and double-quote
+ other string tokens for clarity.
+
+ String constants and text strings used for labels, titles, or other plot
+ elements may be enclosed in either single quotes or double quotes. Further
+ processing of the quoted text depends on the choice of quote marks.
+
+ Backslash processing of special characters like \n (newline) and
+ \345 (octal character code) is performed for double-quoted strings. In
+ single-quoted strings, backslashes are just ordinary characters. To get
+ a single-quote (ascii 39) in a single-quoted string, it has to be doubled.
+ Thus the strings "d\" s' b\\" and 'd" s'' b\' are completely equivalent.
+
+ Text justification is the same for each line of a multi-line string.
+ Thus the center-justified string
+ "This is the first line of text.\nThis is the second line."
+ will produce
+ This is the first line of text.
+ This is the second line.
+ but
+ 'This is the first line of text.\nThis is the second line.'
+ will produce
+ This is the first line of text.\nThis is the second line.
+
+ Enhanced text processing is performed for both double-quoted text and
+ single-quoted text, but only by terminals supporting this mode.
+ See `enhanced text`.
+
+ Back-quotes are used to enclose system commands for substitution into the
+ command line. See `substitution`.
+2 Time/Date data
+^ <a name="Time/Date data"></a>
+^ <a name="Time/date"></a>
+?time/date
+ `gnuplot` supports the use of time and/or date information as input data.
+ This feature is activated by the commands `set xdata time`, `set ydata time`,
+ etc.
+
+ Internally all times and dates are converted to the number of seconds from
+ the year 2000. The command `set timefmt` defines the format for all inputs:
+ data files, ranges, tics, label positions---in short, anything that accepts a
+ data value must receive it in this format. Since only one input format can
+ be in force at a given time, all time/date quantities being input at the same
+ time must be presented in the same format. Thus if both x and y data in a
+ file are time/date, they must be in the same format.
+
+ The conversion to and from seconds assumes Universal Time (which is the same
+ as Greenwich Standard Time). There is no provision for changing the time
+ zone or for daylight savings. If all your data refer to the same time zone
+ (and are all either daylight or standard) you don't need to worry about these
+ things. But if the absolute time is crucial for your application, you'll
+ need to convert to UT yourself.
+
+ Commands like `show xrange` will re-interpret the integer according to
+ `timefmt`. If you change `timefmt`, and then `show` the quantity again, it
+ will be displayed in the new `timefmt`. For that matter, if you give the
+ deactivation command (like `set xdata`), the quantity will be shown in its
+ numerical form.
+
+ The commands `set format` or `set tics format` define the format that will be
+ used for tic labels, whether or not the specified axis is time/date.
+
+ If time/date information is to be plotted from a file, the `using` option
+ _must_ be used on the `plot` or `splot` command. These commands simply use
+ white space to separate columns, but white space may be embedded within the
+ time/date string. If you use tabs as a separator, some trial-and-error may
+ be necessary to discover how your system treats them.
+
+ The following example demonstrates time/date plotting.
+
+ Suppose the file "data" contains records like
+
+ 03/21/95 10:00 6.02e23
+
+ This file can be plotted by
+
+ set xdata time
+ set timefmt "%m/%d/%y"
+ set xrange ["03/21/95":"03/22/95"]
+ set format x "%m/%d"
+ set timefmt "%m/%d/%y %H:%M"
+ plot "data" using 1:3
+
+ which will produce xtic labels that look like "03/21".
+
+ See the descriptions of each command for more details.
+1 Commands
+?commands
+ This section lists the commands acceptable to `gnuplot` in alphabetical
+ order. Printed versions of this document contain all commands; on-line
+ versions may not be complete. Indeed, on some systems there may be no
+ commands at all listed under this heading.
+
+ Note that in most cases unambiguous abbreviations for command names and their
+ options are permissible, i.e., "`p f(x) w li`" instead of "`plot f(x) with
+ lines`".
+
+ In the syntax descriptions, braces ({}) denote optional arguments and a
+ vertical bar (|) separates mutually exclusive choices.
+2 cd
+?commands cd
+?cd
+ The `cd` command changes the working directory.
+
+ Syntax:
+ cd '<directory-name>'
+
+ The directory name must be enclosed in quotes.
+
+ Examples:
+ cd 'subdir'
+ cd ".."
+
+ It is recommended for DOS and Windows users to use
+ single-quotes---backslash [\] has special significance inside
+ double-quotes and has to be escaped. For example,
+ cd "c:\newdata"
+ fails, but
+ cd 'c:\newdata'
+ cd "c:\\newdata"
+ works as expected.
+2 call
+?commands call
+?call
+ The `call` command is identical to the load command with one exception: you
+ can have up to ten additional parameters to the command (delimited according
+ to the standard parser rules) which can be substituted into the lines read
+ from the file. As each line is read from the `call`ed input file, it is
+ scanned for the sequence `$` (dollar-sign) followed by a digit (0--9). If
+ found, the sequence is replaced by the corresponding parameter from the
+ `call` command line. If the parameter was specified as a string in the
+ `call` line, it is substituted without its enclosing quotes. Sequence `$#`
+ is replaced by the number of passed parameters. `$` followed by any character
+ will be that character; e.g. use `$$` to get a single `$`. Providing more
+ than ten parameters on the `call` command line will cause an error. A
+ parameter that was not provided substitutes as nothing. Files being `call`ed
+ may themselves contain `call` or `load` commands.
+
+ The `call` command _must_ be the last command on a multi-command line.
+
+ Syntax:
+ call "<input-file>" <parameter-0> <parm-1> ... <parm-9>
+
+ The name of the input file must be enclosed in quotes, and it is recommended
+ that parameters are similarly enclosed in quotes (future versions of gnuplot
+ may treat quoted and unquoted arguments differently).
+
+ Example:
+
+ If the file 'calltest.gp' contains the line:
+ print "argc=$# p0=$0 p1=$1 p2=$2 p3=$3 p4=$4 p5=$5 p6=$6 p7=x$7x"
+
+ entering the command:
+ call 'calltest.gp' "abcd" 1.2 + "'quoted'" -- "$2"
+
+ will display:
+ argc=7 p0=abcd p1=1.2 p2=+ p3='quoted' p4=- p5=- p6=$2 p7=xx
+
+ NOTE: there is a clash in syntax with the datafile `using` callback
+ operator. Use `$$n` or `column(n)` to access column n from a datafile inside
+ a `call`ed datafile plot.
+2 clear
+?commands clear
+?clear
+ The `clear` command erases the current screen or output device as specified
+ by `set output`. This usually generates a formfeed on hardcopy devices. Use
+ `set terminal` to set the device type.
+
+ For some terminals `clear` erases only the portion of the plotting surface
+ defined by `set size`, so for these it can be used in conjunction with `set
+ multiplot` to create an inset.
+
+ Example:
+ set multiplot
+ plot sin(x)
+ set origin 0.5,0.5
+ set size 0.4,0.4
+ clear
+ plot cos(x)
+ unset multiplot
+
+ Please see `set multiplot`, `set size`, and `set origin` for details of these
+ commands.
+2 exit
+?commands exit
+?exit
+ The commands `exit` and `quit`, as well as the END-OF-FILE character (usually
+ Ctrl-D) terminate input from the current input stream: terminal session, pipe,
+ and file input (pipe).
+
+ If input streams are nested (inherited `load` scripts), then reading will
+ continue in the parent stream. When the top level stream is closed, the
+ program itself will exit.
+
+ The command `exit gnuplot` will immediately and unconditionally cause gnuplot
+ to exit even if the input stream is multiply nested. In this case any open
+ output files may not be completed cleanly. Example of use:
+
+ bind "ctrl-x" "unset output; exit gnuplot"
+
+ See help for `batch/interactive` for more details.
+2 fit
+?commands fit
+?fit
+?least-squares
+?Marquardt
+ The `fit` command can fit a user-defined function to a set of data points
+ (x,y) or (x,y,z), using an implementation of the nonlinear least-squares
+ (NLLS) Marquardt-Levenberg algorithm. Any user-defined variable occurring in
+ the function body may serve as a fit parameter, but the return type of the
+ function must be real.
+
+ Syntax:
+ fit {[xrange] {[yrange]}} <function> '<datafile>'
+ {datafile-modifiers}
+ via '<parameter file>' | <var1>{,<var2>,...}
+
+ Ranges may be specified to temporarily limit the data which is to be fitted;
+ any out-of-range data points are ignored. The syntax is
+ [{dummy_variable=}{<min>}{:<max>}],
+ analogous to `plot`; see `plot ranges`.
+
+ <function> is any valid `gnuplot` expression, although it is usual to use a
+ previously user-defined function of the form f(x) or f(x,y).
+
+ <datafile> is treated as in the `plot` command. All the `plot datafile`
+ modifiers (`using`, `every`,...) except `smooth` and the deprecated `thru`
+ are applicable to `fit`. See `plot datafile`.
+
+ The default data formats for fitting functions with a single independent
+ variable, y=f(x), are {x:}y or x:y:s; those formats can be changed with
+ the datafile `using` qualifier. The third item (a column number or an
+ expression), if present, is interpreted as the standard deviation of the
+ corresponding y value and is used to compute a weight for the datum, 1/s**2.
+ Otherwise, all data points are weighted equally, with a weight of one.
+ Note that if you don't specify a `using` option at all, no y deviations are
+ read from the datafile even if it does have a third column, so you'll
+ always get unit weights.
+
+ To fit a function with two independent variables, z=f(x,y), the required
+ format is `using` with four items, x:y:z:s. The complete format must be
+ given---no default columns are assumed for a missing token. Weights for
+ each data point are evaluated from 's' as above. If error estimates are
+ not available, a constant value can be specified as a constant expression
+ (see `plot datafile using`), e.g., `using 1:2:3:(1)`.
+
+ Multiple datasets may be simultaneously fit with functions of one
+ independent variable by making y a 'pseudo-variable', e.g., the dataline
+ number, and fitting as two independent variables. See `fit multi-branch`.
+
+ The `via` qualifier specifies which parameters are to be adjusted, either
+ directly, or by referencing a parameter file.
+
+ Examples:
+ f(x) = a*x**2 + b*x + c
+ g(x,y) = a*x**2 + b*y**2 + c*x*y
+ FIT_LIMIT = 1e-6
+ fit f(x) 'measured.dat' via 'start.par'
+ fit f(x) 'measured.dat' using 3:($7-5) via 'start.par'
+ fit f(x) './data/trash.dat' using 1:2:3 via a, b, c
+ fit g(x,y) 'surface.dat' using 1:2:3:(1) via a, b, c
+
+ After each iteration step, detailed information about the current state
+ of the fit is written to the display. The same information about the
+ initial and final states is written to a log file, "fit.log". This file
+ is always appended to, so as to not lose any previous fit history; it
+ should be deleted or renamed as desired. By using the command
+ `set fit logfile`, the name of the log file can be changed.
+
+ If gnuplot was built with this option, and you activated it using `set fit
+ errorvariables`, the error for each fitted parameter will be stored in
+ a variable named like the parameter, but with "_err" appended. Thus the
+ errors can be used as input for further computations.
+
+ The fit may be interrupted by pressing Ctrl-C (any key but Ctrl-C under
+ MSDOS and Atari Multitasking Systems). After the current iteration
+ completes, you have the option to (1) stop the fit and accept the current
+ parameter values, (2) continue the fit, (3) execute a `gnuplot` command
+ as specified by the environment variable FIT_SCRIPT. The default for
+ FIT_SCRIPT is `replot`, so if you had previously plotted both the data
+ and the fitting function in one graph, you can display the current state
+ of the fit.
+
+ Once `fit` has finished, the `update` command may be used to store final
+ values in a file for subsequent use as a parameter file. See `update`
+ for details.
+3 adjustable parameters
+?commands fit parameters
+?fit parameters
+?commands fit adjustable_parameters
+?fit adjustable_parameters
+?fit_parameters
+ There are two ways that `via` can specify the parameters to be adjusted,
+ either directly on the command line or indirectly, by referencing a
+ parameter file. The two use different means to set initial values.
+
+ Adjustable parameters can be specified by a comma-separated list of variable
+ names after the `via` keyword. Any variable that is not already defined
+ is created with an initial value of 1.0. However, the fit is more likely
+ to converge rapidly if the variables have been previously declared with more
+ appropriate starting values.
+
+ In a parameter file, each parameter to be varied and a corresponding initial
+ value are specified, one per line, in the form
+ varname = value
+
+ Comments, marked by '#', and blank lines are permissible. The
+ special form
+ varname = value # FIXED
+
+ means that the variable is treated as a 'fixed parameter', initialized by the
+ parameter file, but not adjusted by `fit`. For clarity, it may be useful to
+ designate variables as fixed parameters so that their values are reported by
+ `fit`. The keyword `# FIXED` has to appear in exactly this form.
+
+3 short introduction
+?commands fit beginners_guide
+?fit beginners_guide
+?fit guide
+?fitting
+ `fit` is used to find a set of parameters that 'best' fits your data to your
+ user-defined function. The fit is judged on the basis of the sum of the
+ squared differences or 'residuals' (SSR) between the input data points and
+ the function values, evaluated at the same places. This quantity is often
+ called 'chisquare' (i.e., the Greek letter chi, to the power of 2). The
+ algorithm attempts to minimize SSR, or more precisely, WSSR, as the residuals
+ are 'weighted' by the input data errors (or 1.0) before being squared;
+ see `fit error_estimates` for details.
+
+ That's why it is called 'least-squares fitting'. Let's look at an example
+ to see what is meant by 'non-linear', but first we had better go over some
+ terms. Here it is convenient to use z as the dependent variable for
+ user-defined functions of either one independent variable, z=f(x), or two
+ independent variables, z=f(x,y). A parameter is a user-defined variable
+ that `fit` will adjust, i.e., an unknown quantity in the function
+ declaration. Linearity/non-linearity refers to the relationship of the
+ dependent variable, z, to the parameters which `fit` is adjusting, not of
+ z to the independent variables, x and/or y. (To be technical, the
+ second {and higher} derivatives of the fitting function with respect to
+ the parameters are zero for a linear least-squares problem).
+
+ For linear least-squares (LLS), the user-defined function will be a sum of
+ simple functions, not involving any parameters, each multiplied by one
+ parameter. NLLS handles more complicated functions in which parameters can
+ be used in a large number of ways. An example that illustrates the
+ difference between linear and nonlinear least-squares is the Fourier series.
+ One member may be written as
+ z=a*sin(c*x) + b*cos(c*x).
+ If a and b are the unknown parameters and c is constant, then estimating
+ values of the parameters is a linear least-squares problem. However, if
+ c is an unknown parameter, the problem is nonlinear.
+
+ In the linear case, parameter values can be determined by comparatively
+ simple linear algebra, in one direct step. However LLS is a special case
+ which is also solved along with more general NLLS problems by the iterative
+ procedure that `gnuplot` uses. `fit` attempts to find the minimum by doing
+ a search. Each step (iteration) calculates WSSR with a new set of parameter
+ values. The Marquardt-Levenberg algorithm selects the parameter values for
+ the next iteration. The process continues until a preset criterion is met,
+ either (1) the fit has "converged" (the relative change in WSSR is less than
+ FIT_LIMIT), or (2) it reaches a preset iteration count limit, FIT_MAXITER
+ (see `fit control variables`). The fit may also be interrupted
+ and subsequently halted from the keyboard (see `fit`). The user variable
+ FIT_CONVERGED contains 1 if the previous fit command terminated due to
+ convergence; it contains 0 if the previous fit terminated for any other
+ reason.
+
+ Often the function to be fitted will be based on a model (or theory) that
+ attempts to describe or predict the behaviour of the data. Then `fit` can
+ be used to find values for the free parameters of the model, to determine
+ how well the data fits the model, and to estimate an error range for each
+ parameter. See `fit error_estimates`.
+
+ Alternatively, in curve-fitting, functions are selected independent of
+ a model (on the basis of experience as to which are likely to describe
+ the trend of the data with the desired resolution and a minimum number
+ of parameters*functions.) The `fit` solution then provides an analytic
+ representation of the curve.
+
+ However, if all you really want is a smooth curve through your data points,
+ the `smooth` option to `plot` may be what you've been looking for rather
+ than `fit`.
+3 error estimates
+?commands fit error_estimates
+?fit error_estimates
+?fit errors
+ In `fit`, the term "error" is used in two different contexts, data error
+ estimates and parameter error estimates.
+
+ Data error estimates are used to calculate the relative weight of each data
+ point when determining the weighted sum of squared residuals, WSSR or
+ chisquare. They can affect the parameter estimates, since they determine
+ how much influence the deviation of each data point from the fitted function
+ has on the final values. Some of the `fit` output information, including
+ the parameter error estimates, is more meaningful if accurate data error
+ estimates have been provided.
+
+ The 'statistical overview' describes some of the `fit` output and gives some
+ background for the 'practical guidelines'.
+4 statistical overview
+?commands fit error statistical_overview
+?fit error statistical_overview
+?statistical_overview
+ The theory of non-linear least-squares (NLLS) is generally described in terms
+ of a normal distribution of errors, that is, the input data is assumed to be
+ a sample from a population having a given mean and a Gaussian (normal)
+ distribution about the mean with a given standard deviation. For a sample of
+ sufficiently large size, and knowing the population standard deviation, one
+ can use the statistics of the chisquare distribution to describe a "goodness
+ of fit" by looking at the variable often called "chisquare". Here, it is
+ sufficient to say that a reduced chisquare (chisquare/degrees of freedom,
+ where degrees of freedom is the number of datapoints less the number of
+ parameters being fitted) of 1.0 is an indication that the weighted sum of
+ squared deviations between the fitted function and the data points is the
+ same as that expected for a random sample from a population characterized by
+ the function with the current value of the parameters and the given standard
+ deviations.
+
+ If the standard deviation for the population is not constant, as in counting
+ statistics where variance = counts, then each point should be individually
+ weighted when comparing the observed sum of deviations and the expected sum
+ of deviations.
+
+ At the conclusion `fit` reports 'stdfit', the standard deviation of the fit,
+ which is the rms of the residuals, and the variance of the residuals, also
+ called 'reduced chisquare' when the data points are weighted. The number of
+ degrees of freedom (the number of data points minus the number of fitted
+ parameters) is used in these estimates because the parameters used in
+ calculating the residuals of the datapoints were obtained from the same data.
+ These values are exported to the variables
+ FIT_NDF = Number of degrees of freedom
+ FIT_WSSR = Weighted sum-of-squares residual
+ FIT_STDFIT = sqrt(WSSR/NDF)
+
+ To estimate confidence levels for the parameters, one can use the minimum
+ chisquare obtained from the fit and chisquare statistics to determine the
+ value of chisquare corresponding to the desired confidence level, but
+ considerably more calculation is required to determine the combinations of
+ parameters which produce such values.
+
+ Rather than determine confidence intervals, `fit` reports parameter error
+ estimates which are readily obtained from the variance-covariance matrix
+ after the final iteration. By convention, these estimates are called
+ "standard errors" or "asymptotic standard errors", since they are calculated
+ in the same way as the standard errors (standard deviation of each parameter)
+ of a linear least-squares problem, even though the statistical conditions for
+ designating the quantity calculated to be a standard deviation are not
+ generally valid for the NLLS problem. The asymptotic standard errors are
+ generally over-optimistic and should not be used for determining confidence
+ levels, but are useful for qualitative purposes.
+
+ The final solution also produces a correlation matrix, which gives an
+ indication of the correlation of parameters in the region of the solution;
+ if one parameter is changed, increasing chisquare, does changing another
+ compensate? The main diagonal elements, autocorrelation, are all 1; if
+ all parameters were independent, all other elements would be nearly 0. Two
+ variables which completely compensate each other would have an off-diagonal
+ element of unit magnitude, with a sign depending on whether the relation is
+ proportional or inversely proportional. The smaller the magnitudes of the
+ off-diagonal elements, the closer the estimates of the standard deviation
+ of each parameter would be to the asymptotic standard error.
+4 practical guidelines
+?commands fit error practical_guidelines
+?fit error practical_guidelines
+?practical_guidelines
+?guidelines
+ If you have a basis for assigning weights to each data point, doing so lets
+ you make use of additional knowledge about your measurements, e.g., take into
+ account that some points may be more reliable than others. That may affect
+ the final values of the parameters.
+
+ Weighting the data provides a basis for interpreting the additional `fit`
+ output after the last iteration. Even if you weight each point equally,
+ estimating an average standard deviation rather than using a weight of 1
+ makes WSSR a dimensionless variable, as chisquare is by definition.
+
+ Each fit iteration will display information which can be used to evaluate
+ the progress of the fit. (An '*' indicates that it did not find a smaller
+ WSSR and is trying again.) The 'sum of squares of residuals', also called
+ 'chisquare', is the WSSR between the data and your fitted function; `fit`
+ has minimized that. At this stage, with weighted data, chisquare is expected
+ to approach the number of degrees of freedom (data points minus parameters).
+ The WSSR can be used to calculate the reduced chisquare (WSSR/ndf) or stdfit,
+ the standard deviation of the fit, sqrt(WSSR/ndf). Both of these are
+ reported for the final WSSR.
+
+ If the data are unweighted, stdfit is the rms value of the deviation of the
+ data from the fitted function, in user units.
+
+ If you supplied valid data errors, the number of data points is large enough,
+ and the model is correct, the reduced chisquare should be about unity. (For
+ details, look up the 'chi-squared distribution' in your favourite statistics
+ reference.) If so, there are additional tests, beyond the scope of this
+ overview, for determining how well the model fits the data.
+
+ A reduced chisquare much larger than 1.0 may be due to incorrect data error
+ estimates, data errors not normally distributed, systematic measurement
+ errors, 'outliers', or an incorrect model function. A plot of the residuals,
+ e.g., `plot 'datafile' using 1:($2-f($1))`, may help to show any systematic
+ trends. Plotting both the data points and the function may help to suggest
+ another model.
+
+ Similarly, a reduced chisquare less than 1.0 indicates WSSR is less than that
+ expected for a random sample from the function with normally distributed
+ errors. The data error estimates may be too large, the statistical
+ assumptions may not be justified, or the model function may be too general,
+ fitting fluctuations in a particular sample in addition to the underlying
+ trends. In the latter case, a simpler function may be more appropriate.
+
+ You'll have to get used to both `fit` and the kind of problems you apply it
+ to before you can relate the standard errors to some more practical estimates
+ of parameter uncertainties or evaluate the significance of the correlation
+ matrix.
+
+ Note that `fit`, in common with most NLLS implementations, minimizes the
+ weighted sum of squared distances (y-f(x))**2. It does not provide any means
+ to account for "errors" in the values of x, only in y. Also, any "outliers"
+ (data points outside the normal distribution of the model) will have an
+ exaggerated effect on the solution.
+3 control
+?commands fit control
+?fit control
+ There are a number of `gnuplot` variables that can be defined to affect
+ `fit`. Those which can be defined once `gnuplot` is running are listed
+ under 'control_variables' while those defined before starting `gnuplot`
+ are listed under 'environment_variables'.
+4 control variables
+?commands fit control variables
+?fit control variables
+ The default epsilon limit (1e-5) may be changed by declaring a value for
+ FIT_LIMIT
+ When the sum of squared residuals changes between two iteration steps by
+ a factor less than this number (epsilon), the fit is considered to have
+ 'converged'.
+
+ The maximum number of iterations may be limited by declaring a value for
+ FIT_MAXITER
+ A value of 0 (or not defining it at all) means that there is no limit.
+
+ If you need even more control about the algorithm, and know the
+ Marquardt-Levenberg algorithm well, there are some more variables to
+ influence it. The startup value of `lambda` is normally calculated
+ automatically from the ML-matrix, but if you want to, you may provide
+ your own one with
+ FIT_START_LAMBDA
+ Specifying FIT_START_LAMBDA as zero or less will re-enable the automatic
+ selection. The variable
+ FIT_LAMBDA_FACTOR
+ gives the factor by which `lambda` is increased or decreased whenever
+ the chi-squared target function increased or decreased significantly.
+ Setting FIT_LAMBDA_FACTOR to zero re-enables the default factor of
+ 10.0.
+
+ Other variables with the FIT_ prefix may be added to `fit`, so it is safer
+ not to use that prefix for user-defined variables.
+
+ The variables FIT_SKIP and FIT_INDEX were used by earlier releases of
+ `gnuplot` with a 'fit' patch called `gnufit` and are no longer available.
+ The datafile `every` modifier provides the functionality of FIT_SKIP.
+ FIT_INDEX was used for multi-branch fitting, but multi-branch fitting of
+ one independent variable is now done as a pseudo-3D fit in which the
+ second independent variable and `using` are used to specify the branch.
+ See `fit multi-branch`.
+4 environment variables
+?commands fit control environment
+?fit control environment
+ The environment variables must be defined before `gnuplot` is executed; how
+ to do so depends on your operating system.
+
+ FIT_LOG
+ changes the name (and/or path) of the file to which the fit log will be
+ written from the default of "fit.log" in the working directory. The default
+ value can be overwritten using the command `set fit logfile`.
+
+ FIT_SCRIPT
+ specifies a command that may be executed after an user interrupt. The default
+ is `replot`, but a `plot` or `load` command may be useful to display a plot
+ customized to highlight the progress of the fit.
+3 multi-branch
+?commands fit multi-branch
+?fit multi-branch
+?multi-branch
+?branch
+ In multi-branch fitting, multiple data sets can be simultaneously fit with
+ functions of one independent variable having common parameters by minimizing
+ the total WSSR. The function and parameters (branch) for each data set are
+ selected by using a 'pseudo-variable', e.g., either the dataline number (a
+ 'column' index of -1) or the datafile index (-2), as the second independent
+ variable.
+
+ Example: Given two exponential decays of the form, z=f(x), each describing
+ a different data set but having a common decay time, estimate the values of
+ the parameters. If the datafile has the format x:z:s, then
+ f(x,y) = (y==0) ? a*exp(-x/tau) : b*exp(-x/tau)
+ fit f(x,y) 'datafile' using 1:-2:2:3 via a, b, tau
+
+ For a more complicated example, see the file "hexa.fnc" used by the
+ "fit.dem" demo.
+
+ Appropriate weighting may be required since unit weights may cause one
+ branch to predominate if there is a difference in the scale of the dependent
+ variable. Fitting each branch separately, using the multi-branch solution
+ as initial values, may give an indication as to the relative effect of each
+ branch on the joint solution.
+3 starting values
+?commands fit starting_values
+?fit starting_values
+?starting_values
+ Nonlinear fitting is not guaranteed to converge to the global optimum (the
+ solution with the smallest sum of squared residuals, SSR), and can get stuck
+ at a local minimum. The routine has no way to determine that; it is up to
+ you to judge whether this has happened.
+
+ `fit` may, and often will get "lost" if started far from a solution, where
+ SSR is large and changing slowly as the parameters are varied, or it may
+ reach a numerically unstable region (e.g., too large a number causing a
+ floating point overflow) which results in an "undefined value" message
+ or `gnuplot` halting.
+
+ To improve the chances of finding the global optimum, you should set the
+ starting values at least roughly in the vicinity of the solution, e.g.,
+ within an order of magnitude, if possible. The closer your starting values
+ are to the solution, the less chance of stopping at another minimum. One way
+ to find starting values is to plot data and the fitting function on the same
+ graph and change parameter values and `replot` until reasonable similarity
+ is reached. The same plot is also useful to check whether the fit stopped at
+ a minimum with a poor fit.
+
+ Of course, a reasonably good fit is not proof there is not a "better" fit (in
+ either a statistical sense, characterized by an improved goodness-of-fit
+ criterion, or a physical sense, with a solution more consistent with the
+ model.) Depending on the problem, it may be desirable to `fit` with various
+ sets of starting values, covering a reasonable range for each parameter.
+3 tips
+?commands fit tips
+?fit tips
+?tips
+ Here are some tips to keep in mind to get the most out of `fit`. They're not
+ very organized, so you'll have to read them several times until their essence
+ has sunk in.
+
+ The two forms of the `via` argument to `fit` serve two largely distinct
+ purposes. The `via "file"` form is best used for (possibly unattended) batch
+ operation, where you just supply the startup values in a file and can later
+ use `update` to copy the results back into another (or the same) parameter
+ file.
+
+ The `via var1, var2, ...` form is best used interactively, where the command
+ history mechanism may be used to edit the list of parameters to be fitted or
+ to supply new startup values for the next try. This is particularly useful
+ for hard problems, where a direct fit to all parameters at once won't work
+ without good starting values. To find such, you can iterate several times,
+ fitting only some of the parameters, until the values are close enough to the
+ goal that the final fit to all parameters at once will work.
+
+ Make sure that there is no mutual dependency among parameters of the function
+ you are fitting. For example, don't try to fit a*exp(x+b), because
+ a*exp(x+b)=a*exp(b)*exp(x). Instead, fit either a*exp(x) or exp(x+b).
+
+ A technical issue: the parameters must not be too different in magnitude.
+ The larger the ratio of the largest and the smallest absolute parameter
+ values, the slower the fit will converge. If the ratio is close to or above
+ the inverse of the machine floating point precision, it may take next to
+ forever to converge, or refuse to converge at all. You will have to adapt
+ your function to avoid this, e.g., replace 'parameter' by '1e9*parameter' in
+ the function definition, and divide the starting value by 1e9.
+
+ If you can write your function as a linear combination of simple functions
+ weighted by the parameters to be fitted, by all means do so. That helps a
+ lot, because the problem is no longer nonlinear and should converge with only
+ a small number of iterations, perhaps just one.
+
+ Some prescriptions for analysing data, given in practical experimentation
+ courses, may have you first fit some functions to your data, perhaps in a
+ multi-step process of accounting for several aspects of the underlying
+ theory one by one, and then extract the information you really wanted from
+ the fitting parameters of those functions. With `fit`, this may often be
+ done in one step by writing the model function directly in terms of the
+ desired parameters. Transforming data can also quite often be avoided,
+ though sometimes at the cost of a more difficult fit problem. If you think
+ this contradicts the previous paragraph about simplifying the fit function,
+ you are correct.
+
+ A "singular matrix" message indicates that this implementation of the
+ Marquardt-Levenberg algorithm can't calculate parameter values for the next
+ iteration. Try different starting values, writing the function in another
+ form, or a simpler function.
+
+ Finally, a nice quote from the manual of another fitting package (fudgit),
+ that kind of summarizes all these issues: "Nonlinear fitting is an art!"
+2 help
+?commands help
+?help
+ The `help` command displays on-line help. To specify information on a
+ particular topic use the syntax:
+
+ help {<topic>}
+
+ If <topic> is not specified, a short message is printed about `gnuplot`.
+ After help for the requested topic is given, a menu of subtopics is given;
+ help for a subtopic may be requested by typing its name, extending the help
+ request. After that subtopic has been printed, the request may be extended
+ again or you may go back one level to the previous topic. Eventually, the
+ `gnuplot` command line will return.
+
+ If a question mark (?) is given as the topic, the list of topics currently
+ available is printed on the screen.
+2 history
+?commands history
+?history
+ `history` command lists or saves previous entries in the history of the
+ command line editing, or executes an entry.
+
+ Here you find 'usage by examples':
+
+ history # show the complete history
+ history 5 # show last 5 entries in the history
+ history quiet 5 # show last 5 entries without entry numbers
+ history "hist.gp" # write the complete history to file hist.gp
+ history "hist.gp" append # append the complete history to file hist.gp
+ history 10 "hist.gp" # write last 10 commands to file hist.gp
+ history 10 "|head -5 >>diary.gp" # write 5 history commands using pipe
+ history ?load # show all history entries starting with "load"
+ history ?"set c" # like above, several words enclosed in quotes
+ hi !reread # execute last entry starting with "reread"
+ hist !"set xr" # like above, several words enclosed in quotes
+ hi !hi # guess yourself :-))
+
+ On systems which support a popen function (Unix), the output of history can be
+ piped through an external program by starting the file name with a '|', as one
+ of the above examples demonstrates.
+2 if
+?commands if
+?if
+ The `if` command allows commands to be executed conditionally.
+
+ Syntax:
+ if (<condition>) <command-line> [; else if (<condition>) ...; else ...]
+
+ <condition> will be evaluated. If it is true (non-zero), then the command(s)
+ of the <command-line> will be executed. If <condition> is false (zero), then
+ the entire <command-line> is ignored until the next occurrence of `else`.
+ Note that use of `;` to allow multiple commands on the same line will
+ _not_ end the conditionalized commands.
+
+ Examples:
+ pi=3
+ if (pi!=acos(-1)) print "?Fixing pi!"; pi=acos(-1); print pi
+ will display:
+ ?Fixing pi!
+ 3.14159265358979
+ but
+ if (1==2) print "Never see this"; print "Or this either"
+ will not display anything.
+
+ else:
+ v=0
+ v=v+1; if (v%2) print "2" ; else if (v%3) print "3"; else print "fred"
+ (repeat the last line repeatedly!)
+
+ See `reread` for an example of how `if` and `reread` can be used together to
+ perform a loop.
+2 load
+?commands load
+?load
+ The `load` command executes each line of the specified input file as if it
+ had been typed in interactively. Files created by the `save` command can
+ later be `load`ed. Any text file containing valid commands can be created
+ and then executed by the `load` command. Files being `load`ed may themselves
+ contain `load` or `call` commands. See `comments` for information about
+ comments in commands. To `load` with arguments, see `call`.
+
+ The `load` command _must_ be the last command on a multi-command line.
+
+ Syntax:
+ load "<input-file>"
+
+ The name of the input file must be enclosed in quotes.
+
+ The special filename "-" may be used to `load` commands from standard input.
+ This allows a `gnuplot` command file to accept some commands from standard
+ input. Please see help for `batch/interactive` for more details.
+
+ On some systems which support a popen function (Unix), the load file can be
+ read from a pipe by starting the file name with a '<'.
+
+ Examples:
+ load 'work.gnu'
+ load "func.dat"
+ load "< loadfile_generator.sh"
+
+ The `load` command is performed implicitly on any file names given as
+ arguments to `gnuplot`. These are loaded in the order specified, and
+ then `gnuplot` exits.
+2 lower
+?commands lower
+?lower
+ Syntax:
+ lower {plot_window_nb}
+
+ The `lower` command lowers (opposite to `raise`) plot window(s) associated
+ with the interactive terminal of your gnuplot session, i.e. `pm`, `win`, `wxt`
+ or `x11`. It puts the plot window to bottom in the z-order windows stack of
+ the window manager of your desktop.
+
+ As `x11` and `wxt` support multiple plot windows, then by default they lower
+ these windows in descending order of most recently created on top to the least
+ recently created on bottom. If a plot number is supplied as an optional
+ parameter, only the associated plot window will be lowered if it exists.
+
+ The optional parameter is ignored for single plot-window terminals, i.e. `pm`
+ and `win`.
+2 pause
+?commands pause
+?pause
+?pause mouse
+ The `pause` command displays any text associated with the command and then
+ waits a specified amount of time or until the carriage return is pressed.
+ `pause` is especially useful in conjunction with `load` files.
+
+ Syntax:
+ pause <time> {"<string>"}
+ pause mouse {<endcondition>}{, <endcondition>} {"<string>"}
+
+ <time> may be any constant or expression. Choosing -1 will wait until a
+ carriage return is hit, zero (0) won't pause at all, and a positive number
+ will wait the specified number of seconds. The time is rounded to an integer
+ number of seconds if subsecond time resolution is not supported by the given
+ platform. `pause 0` is synonymous with `print`.
+
+ If the current terminal supports mousing, then `pause mouse` will terminate
+ on either a mouse click or on ctrl-C. For all other terminals, or if mousing
+ is not active, `pause mouse` is equivalent to `pause -1`.
+
+ If one or more end conditions are given after `pause mouse`, then any one of
+ the conditions will terminate the pause. The possible end conditions are
+ `keypress`, `button1`, `button2`, `button3`, `close`, and `any`.
+ If the pause terminates on a keypress, then the ascii value of the key pressed
+ is returned in MOUSE_KEY. The character itself is returned as a one character
+ string in MOUSE_CHAR. Hotkeys (bind command) are disabled if keypress is one of
+ the end conditions. Zooming is disabled if button3 is one of the end
+ conditions.
+
+ In all cases the coordinates of the mouse are returned in variables MOUSE_X,
+ MOUSE_Y, MOUSE_X2, MOUSE_Y2. See `mouse variables`.
+
+ Note: Since `pause` communicates with the operating system rather than the
+ graphics, it may behave differently with different device drivers (depending
+ upon how text and graphics are mixed).
+
+ Examples:
+ pause -1 # Wait until a carriage return is hit
+ pause 3 # Wait three seconds
+ pause -1 "Hit return to continue"
+ pause 10 "Isn't this pretty? It's a cubic spline."
+ pause mouse "Click any mouse button on selected data point"
+ pause mouse keypress "Type a letter from A-F in the active window"
+ pause mouse button1,keypress
+ pause mouse any "Any key or button will terminate"
+
+ The variant "pause mouse key" will resume after any keypress in the active
+ plot window. If you want to wait for a particular key to be pressed, you can
+ use a reread loop such as:
+
+ printf "I will resume after you hit the Tab key in the plot window"
+ load "wait_for_tab"
+
+ File "wait_for_tab" contains the lines
+
+ pause mouse key
+ if (MOUSE_KEY != 9) reread
+
+2 plot
+?commands plot
+?plot
+ `plot` is the primary command for drawing plots with `gnuplot`. It creates
+ plots of functions and data in many, many ways. `plot` is used to draw 2-d
+ functions and data; `splot` draws 2-d projections of 3-d surfaces and data.
+ `plot` and `splot` contain many common features; see `splot` for differences.
+ Note specifically that although the `binary <binary list>` variation does
+ work for both `plot` and `splot`, there are small differences between these
+ modes. Furthermore, `plot`'s `axes` option does not exist for `splot`.
+
+ Syntax:
+ plot {<ranges>}
+ {<function> | {"<datafile>" {datafile-modifiers}}}
+ {axes <axes>} {<title-spec>} {with <style>}
+ {, {definitions,} <function> ...}
+
+ where either a <function> or the name of a data file enclosed in quotes is
+ supplied. A function is a mathematical expression or a pair of mathematical
+ expressions in parametric mode. The expressions may be defined completely or
+ in part earlier in the stream of `gnuplot` commands (see `user-defined`).
+
+ It is also possible to define functions and parameters on the `plot` command
+ itself. This is done merely by isolating them from other items with commas.
+
+ There are four possible sets of axes available; the keyword <axes> is used to
+ select the axes for which a particular line should be scaled. `x1y1` refers
+ to the axes on the bottom and left; `x2y2` to those on the top and right;
+ `x1y2` to those on the bottom and right; and `x2y1` to those on the top and
+ left. Ranges specified on the `plot` command apply only to the first set of
+ axes (bottom left).
+
+ Examples:
+ plot sin(x)
+ plot f(x) = sin(x*a), a = .2, f(x), a = .4, f(x)
+ plot [t=1:10] [-pi:pi*2] tan(t), \
+ "data.1" using (tan($2)):($3/$4) smooth csplines \
+ axes x1y2 notitle with lines 5
+
+ See also `show plot`.
+3 data
+?commands plot datafile
+?plot datafile
+?data-file
+?datafile
+?data
+?file
+ Discrete data contained in a file can be displayed by specifying the name of
+ the data file (enclosed in single or double quotes) on the `plot` command line.
+
+ Syntax:
+ plot '<file_name>' {binary <binary list>}
+ {matrix}
+ {index <index list>}
+ {every <every list>}
+ {thru <thru expression>}
+ {using <using list>}
+ {smooth <option>}
+
+ The modifiers `binary`, `index`, `every`, `thru`, `using`, and `smooth` are
+ discussed separately. In brief, `binary` allows data entry from a binary
+ file (default is ASCII), `index` selects which data sets in a multi-data-set
+ file are to be plotted, `every` specifies which points within a single data
+ set are to be plotted, `using` determines how the columns within a single
+ record are to be interpreted (`thru` is a special case of `using`), and
+ `smooth` allows for simple interpolation and approximation. (`splot` has a
+ similar syntax, but does not support the `smooth` and `thru` options.)
+
+
+ ASCII DATA FILES:
+
+ Data files should contain at least one data point per record (`using`
+ can select one data point from the record). Records beginning with `#`
+ (and also with `!` on VMS) will be treated as comments and ignored.
+ Each data point represents an (x,y) pair. For `plot`s with error bars or
+ error bars with lines (see `set style errorbars` or `set style errorlines`),
+ each data point is (x,y,ydelta), (x,y,ylow,yhigh),
+ (x,y,xdelta), (x,y,xlow,xhigh), or (x,y,xlow,xhigh,ylow,yhigh).
+
+ In all cases, the numbers of each record of a data file must be separated
+ by white space (one or more blanks or tabs) unless a format specifier is
+ provided by the `using` option. This white space divides each record into
+ columns. However, whitespace inside a pair of double quotes is ignored when
+ counting columns, so the following datafile line has three columns:
+ 1.0 "second column" 3.0
+
+ Data may be written in exponential format with the exponent preceded by the
+ letter e or E. The fortran exponential specificiers d, D, q, and Q may also
+ be used if the command `set datafile fortran` is in effect.
+
+ Only one column (the y value) need be provided. If x is omitted, `gnuplot`
+ provides integer values starting at 0.
+
+ In datafiles, blank records (records with no characters other than blanks and
+ a newline and/or carriage return) are significant.
+
+ Single blank records designate discontinuities in a `plot`; no line will join
+ points separated by a blank records (if they are plotted with a line style).
+
+ Two blank records in a row indicate a break between separate data sets.
+ See `index`.
+
+ If autoscaling has been enabled (`set autoscale`), the axes are automatically
+ extended to include all datapoints, with a whole number of tic marks if tics
+ are being drawn. This has two consequences: i) For `splot`, the corner of
+ the surface may not coincide with the corner of the base. In this case, no
+ vertical line is drawn. ii) When plotting data with the same x range on a
+ dual-axis graph, the x coordinates may not coincide if the x2tics are not
+ being drawn. This is because the x axis has been autoextended to a whole
+ number of tics, but the x2 axis has not. The following example illustrates
+ the problem:
+
+ reset; plot '-', '-' axes x2y1
+ 1 1
+ 19 19
+ e
+ 1 1
+ 19 19
+ e
+
+ To avoid this, you can use the `fixmin`/`fixmax` feature of the
+ `set autoscale` command, which turns off the automatic extension of the
+ axis range upto the next tic mark.
+
+
+ BINARY DATA FILES:
+
+ Gnuplot can read binary data files. However, adequate information about
+ details of the file format must be given on the command line or extracted
+ from the file itself for a supported binary `filetype`. In particular,
+ there are two structures for binary files, a matrix binary format and a
+ general binary format.
+
+ The matrix binary format contains a two dimensional array of 32 bit IEEE
+ float values with an additional column and row of coordinate values. As
+ with ASCII matrix, in the `using` list, repetition of the coordinate row
+ constitutes column 1, repetition of the coordinate column constitutes
+ column 2, and the array of values constitutes column 3.
+
+ The general binary format contains an arbitrary number of columns for which
+ information must be specified at the command line. For example, `array`,
+ `record`, `format` and `using` can indicate the size, format and dimension
+ of data. There are a variety of useful commands for skipping file headers
+ and changing endianess. There are a set of commands for positioning and
+ translating data since often coordinates are not part of the file when
+ uniform sampling is inherent in the data. Different from matrix binary or
+ ASCII, general binary does not treat the generated columns as 1, 2 or 3 in
+ the `using` list. Rather, column 1 begins with column 1 of the file, or as
+ specified in the `format` list.
+
+ There are global default settings for the various binary options which may
+ be set using the same syntax as the options when used as part of the `(s)plot
+ <filename> binary ...` command. This syntax is `set datafile binary ...`.
+ The general rule is that common command-line specified parameters override
+ file-extracted parameters which override default parameters.
+
+ Matrix binary is the default binary format when no keywords specific to
+ general binary are given, i.e., `array`, `record`, `format`, `filetype`.
+
+ General binary data can be entered at the command line via the special file
+ name '-'. However, this is intended for use through a pipe where programs
+ can exchange binary data, not for keyboards. There is no "end of record"
+ character for binary data. Gnuplot continues reading from a pipe until it
+ has read the number of points declared in the `array` qualifier.
+
+ See `datafile binary` for more details.
+4 binary
+?commands plot datafile binary
+?plot datafile binary
+?splot datafile binary
+?plot binary
+?splot binary
+?data-file binary
+?datafile binary
+?binary
+ The `binary` keyword allows a data file to be binary as opposed to ASCII.
+ There are two formats for binary--matrix binary and general binary. Matrix
+ binary is a fixed format in which data appears in a 2D array with an extra
+ row and column for coordinate values. General binary is a flexible format
+ for which details about the file must be given at the command line.
+
+ See `binary matrix` or `binary general` for more details.
+4 binary general
+?commands plot datafile binary general
+?commands splot datafile binary general
+?plot binary general
+?splot binary general
+?binary general
+ General binary data in which format information is not necessarily part of
+ the file can be read by giving further details about the file format at the
+ command line. Although the syntax is slightly arcane to the casual user,
+ general binary is particularly useful for application programs using gnuplot
+ and sending large amounts of data.
+
+ Syntax:
+ plot '<file_name>' {binary <binary list>} ...
+ splot '<file_name>' {binary <binary list>} ...
+
+ General binary format is activated by keywords in <binary list> pertaining
+ to information about file structure, i.e., `array`, `record`, `format` or
+ `filetype`. Otherwise, matrix binary format is assumed. (See `binary matrix`
+ for more details.)
+
+ There are some standard file types that may be read for which details about
+ the binary format may be extracted automatically. (Type `show datafile
+ binary` at the command line for a list.) Otherwise, details must be
+ specified at the command line or set in the defaults. Keywords are described
+ below.
+
+ The keyword `filetype` in <binary list> controls the routine used to
+ read the file, i.e., the format of the data. For a list of the supported
+ file types, type `show datafile binary filetypes`. If no file type is
+ given, the rule is that traditional gnuplot binary is assumed for `splot`
+ if the `binary` keyword stands alone. In all other circumstances, for
+ `plot` or when one of the <binary list> keywords appears, a raw binary
+ file is assumed whereby the keywords specify the binary format.
+
+ General binary data files fall into two basic classes, and some files may
+ be of both classes depending upon how they are treated. There is that
+ class for which uniform sampling is assumed and point coordinates must be
+ generated. This is the class for which full control via the <binary
+ list> keywords applies. For this class, the settings precedence is that
+ command line parameters override in-file parameters, which override
+ default settings. The other class is that set of files for which
+ coordinate information is contained within the file or there is possibly
+ a non-uniform sampling such as gnuplot binary.
+
+ Other than for the unique data files such as gnuplot binary, one should
+ think of binary data as conceptually the same as ASCII data. Each point
+ has columns of information which are selected via the `<using list>`
+ associated with `using`. When no `format` string is specified, gnuplot
+ will retrieve a number of binary variables equal to the largest column
+ given in the `<using list>`. For example, `using 1:3` will result in
+ three columns being read, of which the second will be ignored. There are
+ default using lists based upon the typical number of parameters associated
+ with a certain plot type. For example, `with image` has a default of
+ `using 1`, while `with rgbimage` has a default of `using 1:2:3`. Note
+ that the special characters for `using` representing point/line/index
+ generally should not be used for binary data. There are keywords in
+ <binary list> that control this.
+5 array
+?binary general array
+ Describes the sampling array dimensions associated with the binary file.
+ The coordinates will be generated by gnuplot. A number must be specified
+ for each dimension, thereby calling out the size of the array. For example,
+ `array=10x20` means the underlying sampling structure is two-dimensional with
+ 10 points along the first (x) dimension and 20 points along the second (y)
+ dimension. A special "number", `Inf`, can be used to indicate that data should
+ be read until the end of file. A colon can be used to separate the dimensions
+ for multiple records. For example, `array=25:35` indicates there are two
+ one-dimensional records within the file. The colon behavior applies to the
+ remaining keywords in this list for which it makes sense to be associated with
+ individual records.
+
+ Currently, syntax allows for up to three-dimensional arrays. However, no
+ conventions have yet been made for handling three-dimensional coordinates.
+5 record
+?binary general record
+ This keyword serves the same function as `array`, having the same syntax.
+ However, `record` causes gnuplot to not generate coordinate information.
+ This is for the case where such information may be included in one of the
+ columns of the binary data file.
+5 format
+?binary general format
+ The default binary format is a float. For more flexibility, the format can
+ include details about variable sizes. For example, `format="%uchar%int%float"`
+ associates an unsigned character with the first using column, an int with the
+ second column and a float with the third column. If the number of size
+ specifications is less than the greatest column number, the size is implicitly
+ taken to be similar to the last given variable size.
+
+ Furthermore, the format specification can include "discarded" terms via the `*`
+ character. For example, to skip the middle column of the previous example, one
+ could write `format="%uchar%*int%float"` and gnuplot will discard the middle
+ integer. To list variable sizes, type `show datafile binary datasizes`. There
+ are a group of names that are machine dependent along with their sizes in bytes
+ for the particular compilation. There is also a group of names which attempt
+ to be machine independent.
+5 endian
+?binary general endian
+ Often the endianess of binary data in the file does not agree with the
+ endianess used by the platform on which gnuplot is running. Several words can
+ direct gnuplot how to arrange bytes. For example `endian=little` means treat
+ the binary file as having byte significance from least to greatest. The options
+ are
+
+ little: least significant to greatest significance
+ big: greatest significance to least significance
+ default: assume file endianess is the same as compiler
+ swap (swab): Interchange the significance. (If things
+ don't look right, try this.)
+
+ Gnuplot can support "middle" ("pdp") endian if it is compiled with that option.
+5 filetype
+?binary general filetype
+ For some standard binary file formats gnuplot can extract all the necessary
+ information from the file in question. As an example, "format=edf" will read
+ ESRF Header File format files. For a list of the currently supported file
+ formats, type `show datafile binary filetypes`.
+
+ There is a special file type called `auto` for which gnuplot will check if the
+ binary file's extension is a quasi-standard extension for a supported format.
+
+ Command line keywords may be used to override settings extracted from the file.
+ The settings from the file override any defaults. (See `set datafile binary`
+ for details.)
+6 avs
+?binary general filetype avs
+?filetype avs
+?avs
+ `avs` is one of the automatically recognized binary file types for images.
+ AVS is an extremely simple format, suitable mostly for streaming between
+ applications. It consists of 2 longs (xwidth, ywidth) followed by a stream
+ of pixels, each with four bytes of information alpha/red/green/blue.
+6 edf
+?binary general filetype edf
+?filetype edf
+?edf
+?filetype ehf
+?ehf
+ `edf` is one of the automatically recognized binary file types for images.
+ EDF stands for ESRF Data Format, and it supports both edf and ehf formats
+ (the latter means ESRF Header Format). More information on specifications
+ can be found at
+
+ http://www.esrf.fr/computing/expg/subgroups/general/format/Format.html
+
+ See also `binary`.
+5 keywords
+?binary general keywords
+?filetype keywords
+ The following keywords apply only when generating coordinates. That is, when
+ the keyword `array` is used.
+6 scan
+?binary general keywords scan
+ A great deal of confusion can arise concerning the relationship between how
+ gnuplot scans a binary file and the dimensions seen on the plot. To lessen
+ the confusion, conceptually think of gnuplot _always_ scanning the binary file
+ point/line/plane or fast/medium/slow. Then this keyword is used to tell
+ gnuplot how to map this scanning convention to the Cartesian convention shown
+ in plots, i.e., x/y/z. The qualifier for scan is a two or three letter code
+ representing where point is assigned (first letter), line is assigned (second
+ letter), and plane is assigned (third letter). For example, `scan=yx` means
+ the fastest, point-by-point, increment should be mapped along the Cartesian
+ y dimension and the middle, line-by-line, increment should be mapped along the
+ x dimension.
+
+ When the plotting mode is `plot`, the qualifier code can include the two
+ letters x and y. For `splot`, it can include the three letters x, y and z.
+
+ There is nothing restricting the inherent mapping from point/line/plane to
+ apply only to Cartesian coordinates. For this reason there are cylindrical
+ coordinate synonyms for the qualifier codes where t (theta), r and z are
+ analogous to the x, y and z of Cartesian coordinates.
+6 transpose
+?binary general keywords transpose
+ Shorthand notation for `scan=yx` or `scan=yxz`.
+6 dx, dy, dz
+?binary general keywords dx
+ When gnuplot generates coordinates, it uses the spacing described by these
+ keywords. For example `dx=10 dy=20` would mean space samples along the
+ x dimension by 10 and space samples along the y dimension by 20. `dy` cannot
+ appear if `dx` does not appear. Similarly, `dz` cannot appear if `dy` does not
+ appear. If the underlying dimensions are greater than the keywords specified,
+ the spacing of the highest dimension given is extended to the other dimensions.
+ For example, if an image is being read from a file and only `dx=3.5` is given
+ gnuplot uses a delta x and delta y of 3.5.
+
+ The following keywords also apply only when generating coordinates. However
+ they may also be used with matrix binary files.
+6 flipx, flipy, flipz
+?binary general keywords flipx
+ Sometimes the scanning directions in a binary datafile are not consistent with
+ that assumed by gnuplot. These keywords can flip the scanning direction along
+ dimensions x, y, z.
+6 origin
+?binary general keywords origin
+ When gnuplot generates coordinates based upon transposition and flip, it
+ attempts to always position the lower left point in the array at the origin,
+ i.e., the data lies in the first quadrant of a Cartesian system after transpose
+ and flip.
+
+ To position the array somewhere else on the graph, the `origin` keyword directs
+ gnuplot to position the lower left point of the array at a point specified by a
+ tuple. The tuple should be a double for `plot` and a triple for `splot`.
+ For example, `origin=(100,100):(100,200)` is for two records in the file and
+ intended for plotting in two dimensions. A second example, `origin=(0,0,3.5)`,
+ is for plotting in three dimensions.
+6 center
+?binary general keywords center
+ Similar to `origin`, this keyword will position the array such that its center
+ lies at the point given by the tuple. For example, `center=(0,0)`. Center
+ does not apply when the size of the array is `Inf`.
+6 rotate
+?binary general keywords rotate
+ The transpose and flip commands provide some flexibility in generating and
+ orienting coordinates. However, for full degrees of freedom, it is possible to
+ apply a rotational vector described by a rotational angle in two dimensions.
+
+ The `rotate` keyword applies to the two-dimensional plane, whether it be `plot`
+ or `splot`. The rotation is done with respect to the positive angle of the
+ Cartesian plane.
+
+ The angle can be expressed in radians, radians as a multiple of pi, or degrees.
+ For example, `rotate=1.5708`, `rotate=0.5pi` and `rotate=90deg` are equivalent.
+
+ If `origin` is specified, the rotation is done about the lower left sample
+ point before translation. Otherwise, the rotation is done about the array
+ `center`.
+6 perpendicular
+?binary general keywords perpendicular
+ For `splot`, the concept of a rotational vector is implemented by a triple
+ representing the vector to be oriented normal to the two-dimensional x-y plane.
+ Naturally, the default is (0,0,1). Thus specifying both rotate and
+ perpendicular together can orient data myriad ways in three-space.
+
+ The two-dimensional rotation is done first, followed by the three-dimensional
+ rotation. That is, if R' is the rotational 2 x 2 matrix described by an angle,
+ and P is the 3 x 3 matrix projecting (0,0,1) to (xp,yp,zp), let R be
+ constructed from R' at the upper left sub-matrix, 1 at element 3,3 and zeros
+ elsewhere. Then the matrix formula for translating data is v' = P R v, where v
+ is the 3 x 1 vector of data extracted from the data file. In cases where the
+ data of the file is inherently not three-dimensional, logical rules are used to
+ place the data in three-space. (E.g., usually setting the z-dimension value to
+ zero and placing 2D data in the x-y plane.)
+5 binary examples
+?binary_examples
+?binary examples
+?binary general examples
+ Examples:
+
+ # Selects two float values (second one implicit) with a float value
+ # discarded between them for an indefinite length of 1D data.
+ plot '<file_name>' binary format="%float%*float" using 1:2 with lines
+
+ # The data file header contains all details necessary for creating
+ # coordinates from an EDF file.
+ plot '<file_name>' binary filetype=edf with image
+ plot '<file_name>.edf' binary filetype=auto with image
+
+ # Selects three unsigned characters for components of a raw RGB image
+ # and flips the y-dimension so that typical image orientation (start
+ # at top left corner) translates to the Cartesian plane. Pixel
+ # spacing is given and there are two images in the file. One of them
+ # is translated via origin.
+ plot '<file_name>' binary array=512x1024:1024x512 format='%uchar' \
+ dx=2:1 dy=1:2 origin=(0,0):(1024,1024) flipy u 1:2:3 w rgbimage
+
+ # Four separate records in which the coordinates are part of the
+ # data file. The file was created with a endianess different from
+ # the system on which gnuplot is running.
+ splot '<file_name>' binary record=30:30:29:26 endian=swap u 1:2:3
+
+ See also `binary matrix`.
+4 every
+?commands plot datafile every
+?plot datafile every
+?plot every
+?data-file every
+?datafile every
+?every
+ The `every` keyword allows a periodic sampling of a data set to be plotted.
+
+ In the discussion a "point" is a datum defined by a single record in the
+ file; "block" here will mean the same thing as "datablock" (see `glossary`).
+
+ Syntax:
+ plot 'file' every {<point_incr>}
+ {:{<block_incr>}
+ {:{<start_point>}
+ {:{<start_block>}
+ {:{<end_point>}
+ {:<end_block>}}}}}
+
+ The data points to be plotted are selected according to a loop from
+ <`start_point`> to <`end_point`> with increment <`point_incr`> and the
+ blocks according to a loop from <`start_block`> to <`end_block`> with
+ increment <`block_incr`>.
+
+ The first datum in each block is numbered '0', as is the first block in the
+ file.
+
+ Note that records containing unplottable information are counted.
+
+ Any of the numbers can be omitted; the increments default to unity, the start
+ values to the first point or block, and the end values to the last point or
+ block. If `every` is not specified, all points in all lines are plotted.
+
+ Examples:
+ every :::3::3 # selects just the fourth block ('0' is first)
+ every :::::9 # selects the first 10 blocks
+ every 2:2 # selects every other point in every other block
+ every ::5::15 # selects points 5 through 15 in each block
+
+ See
+^ <a href="http://www.gnuplot.info/demo/simple.html">
+ simple plot demos (simple.dem)
+^ </a>
+ ,
+^ <a href="http://www.gnuplot.info/demo/surface1.html">
+ Non-parametric splot demos
+^ </a>
+ , and
+^ <a href="http://gnuplot.sourceforge.net/demo/surface2.html">
+ Parametric splot demos
+^ </a>
+ .
+4 example datafile
+?commands plot datafile example
+?plot datafile example
+?plot example
+?datafile example
+?data-file example
+?example
+ This example plots the data in the file "population.dat" and a theoretical
+ curve:
+
+ pop(x) = 103*exp((1965-x)/10)
+ plot [1960:1990] 'population.dat', pop(x)
+
+ The file "population.dat" might contain:
+
+ # Gnu population in Antarctica since 1965
+ 1965 103
+ 1970 55
+ 1975 34
+ 1980 24
+ 1985 10
+
+^ <img align=bottom src="http://www.gnuplot.info/doc/population.gif" alt="[population.gif]" width=640 height=480>
+4 index
+?commands plot datafile index
+?plot datafile index
+?plot index
+?data-file index
+?datafile index
+?index
+ The `index` keyword allows you to select specific data sets in a multi-data-set
+ file for plotting.
+
+ Syntax:
+ plot 'file' index <m>{{:<n>}:<p>}
+
+ Data sets are separated by pairs of blank records. `index <m>` selects only
+ set <m>; `index <m>:<n>` selects sets in the range <m> to <n>; and `index
+ <m>:<n>:<p>` selects indices <m>, <m>+<p>, <m>+2<p>, etc., but stopping at
+ <n>. Following C indexing, the index 0 is assigned to the first data set in
+ the file. Specifying too large an index results in an error message. If
+ `index` is not specified, all sets are plotted as a single data set.
+
+ Example:
+ plot 'file' index 4:5
+
+ For each point in the file, the index value of the data set it appears in is
+ available via the pseudo-column `column(-2)`. This leads to an alternative way
+ of distinguishing individual data sets within a file as shown below. This is
+ more awkward that the `index` command if all you are doing is selecting one
+ data set for plotting, but is very useful if you want to assign different
+ properties to each data set. See `lc variable`.
+
+ Example:
+ plot 'file' using 1:(column(-2)==4 ? $2 : NaN) # very awkward
+ plot 'file' using 1:2:(column(-2)) linecolor variable # very useful!
+
+^ See also web page
+^ <a href="http://www.gnuplot.info/demo/multimsh.html">
+^ splot with indices demo.
+^ </a>
+4 smooth
+?commands plot datafile smooth
+?plot datafile smooth
+?plot smooth
+?data-file smooth
+?datafile smooth
+?smooth
+ `gnuplot` includes a few general-purpose routines for interpolation and
+ approximation of data; these are grouped under the `smooth` option. More
+ sophisticated data processing may be performed by preprocessing the data
+ externally or by using `fit` with an appropriate model.
+
+ Syntax:
+ smooth {unique | frequency | csplines | acsplines | bezier | sbezier}
+
+ `unique` and `frequency` plot the data after making them monotonic. Each of
+ the other routines uses the data to determine the coefficients of a
+ continuous curve between the endpoints of the data. This curve is then
+ plotted in the same manner as a function, that is, by finding its value at
+ uniform intervals along the abscissa (see `set samples`) and connecting these
+ points with straight line segments (if a line style is chosen).
+
+ If `autoscale` is in effect, the ranges will be computed such that the
+ plotted curve lies within the borders of the graph.
+
+ If `autoscale` is not in effect, and the smooth option is either `acspline`
+ or `cspline`, the sampling of the generated curve is
+ done across the intersection of the x range covered by the input data and
+ the fixed abscissa range as defined by `set xrange`.
+
+ If too few points are available to allow the selected option to be applied,
+ an error message is produced. The minimum number is one for `unique` and
+ `frequency`, four for `acsplines`, and three for the others.
+
+ The `smooth` options have no effect on function plots.
+5 acsplines
+?commands plot datafile smooth acsplines
+?plot datafile smooth acsplines
+?data-file smooth acsplines
+?datafile smooth acsplines
+?plot smooth acsplines
+?plot acsplines
+?smooth acsplines
+?acsplines
+ The `acsplines` option approximates the data with a "natural smoothing spline".
+ After the data are made monotonic in x (see `smooth unique`), a curve is
+ piecewise constructed from segments of cubic polynomials whose coefficients
+ are found by the weighting the data points; the weights are taken from the
+ third column in the data file. That default can be modified by the third
+ entry in the `using` list, e.g.,
+ plot 'data-file' using 1:2:(1.0) smooth acsplines
+
+ Qualitatively, the absolute magnitude of the weights determines the number
+ of segments used to construct the curve. If the weights are large, the
+ effect of each datum is large and the curve approaches that produced by
+ connecting consecutive points with natural cubic splines. If the weights are
+ small, the curve is composed of fewer segments and thus is smoother; the
+ limiting case is the single segment produced by a weighted linear least
+ squares fit to all the data. The smoothing weight can be expressed in terms
+ of errors as a statistical weight for a point divided by a "smoothing factor"
+ for the curve so that (standard) errors in the file can be used as smoothing
+ weights.
+
+ Example:
+ sw(x,S)=1/(x*x*S)
+ plot 'data_file' using 1:2:(sw($3,100)) smooth acsplines
+5 bezier
+?commands plot datafile smooth bezier
+?plot datafile smooth bezier
+?plot smooth bezier
+?data-file smooth bezier
+?datafile smooth bezier
+?plot bezier
+?smooth bezier
+?bezier
+ The `bezier` option approximates the data with a Bezier curve of degree n
+ (the number of data points) that connects the endpoints.
+5 csplines
+?commands plot datafile smooth csplines
+?plot datafile smooth csplines
+?plot smooth csplines
+?data-file smooth csplines
+?datafile smooth csplines
+?plot csplines
+?smooth csplines
+?csplines
+ The `csplines` option connects consecutive points by natural cubic splines
+ after rendering the data monotonic (see `smooth unique`).
+5 sbezier
+?commands plot datafile smooth sbezier
+?plot datafile smooth sbezier
+?plot smooth sbezier
+?data-file smooth sbezier
+?datafile smooth sbezier
+?plot sbezier
+?smooth sbezier
+?sbezier
+ The `sbezier` option first renders the data monotonic (`unique`) and then
+ applies the `bezier` algorithm.
+5 unique
+?commands plot datafile smooth unique
+?plot datafile smooth unique
+?plot smooth unique
+?data-file smooth unique
+?datafile smooth unique
+?plot unique
+?smooth unique
+?unique
+ The `unique` option makes the data monotonic in x; points with the same
+ x-value are replaced by a single point having the average y-value. The
+ resulting points are then connected by straight line segments.
+^ See this
+^ <a href="http://www.gnuplot.info/demo/mgr.html">
+ demos
+^ </a>
+^ web page.
+5 frequency
+?commands plot datafile smooth frequency
+?plot datafile smooth frequency
+?plot smooth frequency
+?data-file smooth frequency
+?datafile smooth frequency
+?plot frequency
+?smooth frequency
+?frequency
+ The `frequency` option makes the data monotonic in x; points with the same
+ x-value are replaced by a single point having the summed y-values. The
+ resulting points are then connected by straight line segments.
+4 special-filenames
+?commands plot datafile special-filenames
+?plot datafile special-filenames
+?plot special-filenames
+?datafile special-filenames
+?special-filenames
+ A special filename of `'-'` specifies that the data are inline; i.e., they
+ follow the command. Only the data follow the command; `plot` options like
+ filters, titles, and line styles remain on the `plot` command line. This is
+ similar to << in unix shell script, and $DECK in VMS DCL. The data are
+ entered as though they are being read from a file, one data point per record.
+ The letter "e" at the start of the first column terminates data entry. The
+ `using` option can be applied to these data---using it to filter them through
+ a function might make sense, but selecting columns probably doesn't!
+
+ `'-'` is intended for situations where it is useful to have data and commands
+ together, e.g., when `gnuplot` is run as a sub-process of some front-end
+ application. Some of the demos, for example, might use this feature. While
+ `plot` options such as `index` and `every` are recognized, their use forces
+ you to enter data that won't be used. For example, while
+
+ plot '-' index 0, '-' index 1
+ 2
+ 4
+ 6
+
+
+ 10
+ 12
+ 14
+ e
+ 2
+ 4
+ 6
+
+
+ 10
+ 12
+ 14
+ e
+
+ does indeed work,
+
+ plot '-', '-'
+ 2
+ 4
+ 6
+ e
+ 10
+ 12
+ 14
+ e
+
+ is a lot easier to type.
+
+ If you use `'-'` with `replot`, you may need to enter the data more than once
+ (see `replot`).
+
+ A blank filename ('') specifies that the previous filename should be reused.
+ This can be useful with things like
+
+ plot 'a/very/long/filename' using 1:2, '' using 1:3, '' using 1:4
+
+ (If you use both `'-'` and `''` on the same `plot` command, you'll need to
+ have two sets of inline data, as in the example above.)
+
+ On some computer systems with a popen function (Unix), the datafile can be
+ piped through a shell command by starting the file name with a '<'. For
+ example,
+
+ pop(x) = 103*exp(-x/10)
+ plot "< awk '{print $1-1965, $2}' population.dat", pop(x)
+
+ would plot the same information as the first population example but with
+ years since 1965 as the x axis. If you want to execute this example, you
+ have to delete all comments from the data file above or substitute the
+ following command for the first part of the command above (the part up to
+ the comma):
+
+ plot "< awk '$0 !~ /^#/ {print $1-1965, $2}' population.dat"
+
+ While this approach is most flexible, it is possible to achieve simple
+ filtering with the `using` or `thru` keywords.
+4 thru
+?commands plot datafile thru
+?plot datafile thru
+?plot thru
+?data-file thru
+?datafile thru
+?thru
+ The `thru` function is provided for backward compatibility.
+
+ Syntax:
+ plot 'file' thru f(x)
+
+ It is equivalent to:
+
+ plot 'file' using 1:(f($2))
+
+ While the latter appears more complex, it is much more flexible. The more
+ natural
+
+ plot 'file' thru f(y)
+
+ also works (i.e. you can use y as the dummy variable).
+
+ `thru` is parsed for `splot` and `fit` but has no effect.
+4 using
+?commands plot datafile using
+?plot datafile using
+?plot using
+?data-file using
+?datafile using
+?using
+ The most common datafile modifier is `using`.
+
+ Syntax:
+ plot 'file' using {<entry> {:<entry> {:<entry> ...}}} {'format'}
+
+ If a format is specified, each datafile record is read using the C library's
+ 'scanf' function, with the specified format string. Otherwise the record is
+ read and broken into columns. By default the separation between columns is
+ whitespace (spaces and/or tabs), but see `datafile separator`.
+
+ Each <entry> may be a simple column number that selects the value from one
+ field of the input fit, an expression enclosed in parentheses, or empty.
+
+ If the entry is an expression in parentheses, then the function column(N) may
+ be used to indicate the value in column N. That is, column(1) refers to the
+ first item read, column(2) to the second, and so on. The special symbols
+ $1, $2, ... are shorthand for column(1), column(2) ... The function `valid(N)`
+ tests whether the value in the Nth column is a valid number.
+
+ In addition to the actual columns 1...N in the input data file, gnuplot
+ presents data from several "pseudo-columns" that hold bookkeeping information.
+ E.g. $0 or column(0) returns the sequence number of this data record within a
+ dataset.
+
+ An empty <entry> will default to its order in the list of entries.
+ For example, `using ::4` is interpreted as `using 1:2:4`.
+
+ If the `using` list has but a single entry, that <entry> will be used for y
+ and the data point number (pseudo-column $0) is used for x; for example,
+ "`plot 'file' using 1`" is identical to "`plot 'file' using 0:1`".
+ If the `using` list has two entries, these will be used for x and y.
+ See `set style` and `fit` for details about plotting styles that make use of
+ data from additional columns of input.
+
+ 'scanf' accepts several numerical specifications but `gnuplot`
+ requires all inputs to be double-precision floating-point variables,
+ so "%lf" is essentially the only permissible specifier.
+ A format string given by the user must contain at least one such
+ input specifier, and no more than seven of them.
+ 'scanf' expects to see white space---a blank, tab
+ ("\t"), newline ("\n"), or formfeed ("\f")---between numbers; anything else
+ in the input stream must be explicitly skipped.
+
+ Note that the use of "\t", "\n", or "\f" requires use of double-quotes
+ rather than single-quotes.
+5 using_examples
+?examples
+?commands plot datafile using examples
+?plot datafile using examples
+?datafile using examples
+?using examples
+ This creates a plot of the sum of the 2nd and 3rd data against the first:
+ The format string specifies comma- rather than space-separated columns.
+ The same result could be achieved by specifying `set datafile separator ","`.
+ plot 'file' using 1:($2+$3) '%lf,%lf,%lf'
+
+ In this example the data are read from the file "MyData" using a more
+ complicated format:
+ plot 'MyData' using "%*lf%lf%*20[^\n]%lf"
+
+ The meaning of this format is:
+
+ %*lf ignore a number
+ %lf read a double-precision number (x by default)
+ %*20[^\n] ignore 20 non-newline characters
+ %lf read a double-precision number (y by default)
+
+ One trick is to use the ternary `?:` operator to filter data:
+
+ plot 'file' using 1:($3>10 ? $2 : 1/0)
+
+ which plots the datum in column two against that in column one provided
+ the datum in column three exceeds ten. `1/0` is undefined; `gnuplot`
+ quietly ignores undefined points, so unsuitable points are suppressed.
+ Or you can use the pre-defined variable NaN to achieve the same result.
+=NaN
+
+ In fact, you can use a constant expression for the column number, provided it
+ doesn't start with an opening parenthesis; constructs like `using
+ 0+(complicated expression)` can be used. The crucial point is that the
+ expression is evaluated once if it doesn't start with a left parenthesis, or
+ once for each data point read if it does.
+
+ If timeseries data are being used, the time can span multiple columns. The
+ starting column should be specified. Note that the spaces within the time
+ must be included when calculating starting columns for other data. E.g., if
+ the first element on a line is a time with an embedded space, the y value
+ should be specified as column three.
+
+ It should be noted that `plot 'file'`, `plot 'file' using 1:2`, and `plot
+ 'file' using ($1):($2)` can be subtly different: 1) if `file` has some lines
+ with one column and some with two, the first will invent x values when they
+ are missing, the second will quietly ignore the lines with one column, and
+ the third will store an undefined value for lines with one point (so that in
+ a plot with lines, no line joins points across the bad point); 2) if a line
+ contains text at the first column, the first will abort the plot on an error,
+ but the second and third should quietly skip the garbage.
+
+ In fact, it is often possible to plot a file with lots of lines of garbage at
+ the top simply by specifying
+
+ plot 'file' using 1:2
+
+ However, if you want to leave text in your data files, it is safer to put the
+ comment character (#) in the first column of the text lines.
+^ See also the web page
+^ <a href="http://www.gnuplot.info/demo/using.html">
+ Feeble using demos.
+^ </a>
+
+ If gnuplot is built with configuration option --enable-datastrings, then
+ additional modifiers to `using` can specify handling of text fields in the
+ datafile. See `datastrings`, `using xticlabels`, `using title`.
+5 using title
+?using title
+?plot using title
+ If gnuplot is built with configuration option --enable-datastrings, then
+ the first entry of a column of the input data file can be used as a string
+ to provide the plot title in the key box. The column containing specified
+ is independent of the column[s] used for the plot itself.
+
+ plot 'data' using 1:($2/$3) title column(N)
+
+ In this case the entry in the first row of column N will be used for the
+ key entry of the plot constructed from dividing column 2 by column 3.
+ The entry in the first row of columns 2 and 3 will be ignored.
+
+5 xticlabels
+?using xticlabels
+?plot using xticlabels
+ If gnuplot is built with configuration option --enable-datastrings, then
+ a column of the input data file can be used to label axis tic marks.
+ The format of such a plot command is
+
+ plot 'datafile' using <xcol>:<ycol>:xticlabels(<labelcol>) with <plotstyle>
+
+ Tic labels may be read for any of the plot axes: x x2 y y2 z.
+ The `ticlabels(<labelcol>)` specifiers must come after all of the data
+ coordinate specifiers in the `using` portion of the command.
+ For each data point which has a valid set of X,Y[,Z] coordinates,
+ the text field found in column <labelcol> is added to the list of xtic labels
+ at the same X coordinate as the point it belongs to. `xticlabels(<labelcol>)`
+ may be shortened to `xtic(<labelcol>)`.
+
+ Example:
+
+ splot "data" using 2:4:6:xtic(1):ytic(3):ztic(6)
+
+ In this example the x and y axis tic labels are taken from different columns
+ than the x and y coordinate values. The z axis tics, however, are generated
+ from the z coordinate of the corresponding point.
+5 x2ticlabels
+?using x2ticlabels
+?plot using x2ticlabels
+ See `plot using xticlabels`.
+5 yticlabels
+?using yticlabels
+?plot using yticlabels
+ See `plot using xticlabels`.
+5 y2ticlabels
+?using y2ticlabels
+?plot using y2ticlabels
+ See `plot using xticlabels`.
+5 zticlabels
+?using zticlabels
+?plot using zticlabels
+ See `plot using xticlabels`.
+3 errorbars
+?commands plot errorbars
+?commands splot errorbars
+?plot errorbars
+?splot errorbars
+?errorbars
+ Error bars are supported for 2-d data file plots by reading one to four
+ additional columns (or `using` entries); these additional values are used in
+ different ways by the various errorbar styles.
+
+ In the default situation, `gnuplot` expects to see three, four, or six
+ numbers on each line of the data file---either
+
+ (x, y, ydelta),
+ (x, y, ylow, yhigh),
+ (x, y, xdelta),
+ (x, y, xlow, xhigh),
+ (x, y, xdelta, ydelta), or
+ (x, y, xlow, xhigh, ylow, yhigh).
+
+ The x coordinate must be specified. The order of the numbers must be
+ exactly as given above, though the `using` qualifier can manipulate the order
+ and provide values for missing columns. For example,
+
+ plot 'file' with errorbars
+ plot 'file' using 1:2:(sqrt($1)) with xerrorbars
+ plot 'file' using 1:2:($1-$3):($1+$3):4:5 with xyerrorbars
+
+ The last example is for a file containing an unsupported combination of
+ relative x and absolute y errors. The `using` entry generates absolute x min
+ and max from the relative error.
+
+ The y error bar is a vertical line plotted from (x, ylow) to (x,
+ yhigh). If ydelta is specified instead of ylow and yhigh, ylow = y -
+ ydelta and yhigh = y + ydelta are derived. If there are only two
+ numbers on the record, yhigh and ylow are both set to y. The x error
+ bar is a horizontal line computed in the same fashion. To get lines
+ plotted between the data points, `plot` the data file twice, once with
+ errorbars and once with lines (but remember to use the `notitle`
+ option on one to avoid two entries in the key). Alternately, use the
+ errorlines command (see `errorlines`).
+
+ The error bars have crossbars at each end unless `set bars` is used
+ (see `set bars` for details).
+
+ If autoscaling is on, the ranges will be adjusted to include the error bars.
+
+ See also
+^ <a href="http://gnuplot.sourceforge.net/demo/mgr.html">
+ errorbar demos.
+^ </a>
+
+ See `plot using`, `plot with`, and `set style` for more information.
+3 errorlines
+?commands plot errorlines
+?commands splot errorlines
+?plot errorlines
+?splot errorlines
+?errorlines
+ Lines with error bars are supported for 2-d data file plots by reading
+ one to four additional columns (or `using` entries); these additional
+ values are used in different ways by the various errorlines styles.
+
+ In the default situation, `gnuplot` expects to see three, four, or six
+ numbers on each line of the data file---either
+
+ (x, y, ydelta),
+ (x, y, ylow, yhigh),
+ (x, y, xdelta),
+ (x, y, xlow, xhigh),
+ (x, y, xdelta, ydelta), or
+ (x, y, xlow, xhigh, ylow, yhigh).
+
+ The x coordinate must be specified. The order of the numbers must be
+ exactly as given above, though the `using` qualifier can manipulate
+ the order and provide values for missing columns. For example,
+
+ plot 'file' with errorlines
+ plot 'file' using 1:2:(sqrt($1)) with xerrorlines
+ plot 'file' using 1:2:($1-$3):($1+$3):4:5 with xyerrorlines
+
+ The last example is for a file containing an unsupported combination
+ of relative x and absolute y errors. The `using` entry generates
+ absolute x min and max from the relative error.
+
+ The y error bar is a vertical line plotted from (x, ylow) to (x,
+ yhigh). If ydelta is specified instead of ylow and yhigh, ylow = y -
+ ydelta and yhigh = y + ydelta are derived. If there are only two
+ numbers on the record, yhigh and ylow are both set to y. The x error
+ bar is a horizontal line computed in the same fashion.
+
+ The error bars have crossbars at each end unless `set bars` is used
+ (see `set bars` for details).
+
+ If autoscaling is on, the ranges will be adjusted to include the error bars.
+
+ See `plot using`, `plot with`, and `set style` for more information.
+3 parametric
+?commands plot parametric
+?commands splot parametric
+?plot parametric
+?splot parametric
+ When in parametric mode (`set parametric`) mathematical expressions must be
+ given in pairs for `plot` and in triplets for `splot`.
+
+ Examples:
+ plot sin(t),t**2
+ splot cos(u)*cos(v),cos(u)*sin(v),sin(u)
+
+ Data files are plotted as before, except any preceding parametric function
+ must be fully specified before a data file is given as a plot. In other
+ words, the x parametric function (`sin(t)` above) and the y parametric
+ function (`t**2` above) must not be interrupted with any modifiers or data
+ functions; doing so will generate a syntax error stating that the parametric
+ function is not fully specified.
+
+ Other modifiers, such as `with` and `title`, may be specified only after the
+ parametric function has been completed:
+
+ plot sin(t),t**2 title 'Parametric example' with linespoints
+
+ See also
+^ <a href="http://www.gnuplot.info/demo/param.html">
+ Parametric Mode Demos.
+^ </a>
+3 ranges
+?commands plot ranges
+?commands splot ranges
+?plot ranges
+?splot ranges
+?ranges
+ The optional ranges specify the region of the graph that will be displayed.
+
+ Syntax:
+ [{<dummy-var>=}{{<min>}:{<max>}}]
+ [{{<min>}:{<max>}}]
+
+ The first form applies to the independent variable (`xrange` or `trange`, if
+ in parametric mode). The second form applies to the dependent variable
+ `yrange` (and `xrange`, too, if in parametric mode). <dummy-var> is a new
+ name for the independent variable. (The defaults may be changed with `set
+ dummy`.) The optional <min> and <max> terms can be constant expressions or *.
+
+ In non-parametric mode, the order in which ranges must be given is `xrange`
+ and `yrange`.
+
+ In parametric mode, the order for the `plot` command is `trange`, `xrange`,
+ and `yrange`. The following `plot` command shows setting the `trange` to
+ [-pi:pi], the `xrange` to [-1.3:1.3] and the `yrange` to [-1:1] for the
+ duration of the graph:
+
+ plot [-pi:pi] [-1.3:1.3] [-1:1] sin(t),t**2
+
+ Note that the x2range and y2range cannot be specified here---`set x2range`
+ and `set y2range` must be used.
+
+ Ranges are interpreted in the order listed above for the appropriate mode.
+ Once all those needed are specified, no further ones must be listed, but
+ unneeded ones cannot be skipped---use an empty range `[]` as a placeholder.
+
+ `*` can be used to allow autoscaling of either of min and max. See also
+ `set autoscale`.
+
+ Ranges specified on the `plot` or `splot` command line affect only that
+ graph; use the `set xrange`, `set yrange`, etc., commands to change the
+ default ranges for future graphs.
+
+ With time data, you must provide the range (in the same manner as the time
+ appears in the datafile) within quotes. `gnuplot` uses the `timefmt` string
+ to read the value---see `set timefmt`.
+
+ Examples:
+
+ This uses the current ranges:
+ plot cos(x)
+
+ This sets the x range only:
+ plot [-10:30] sin(pi*x)/(pi*x)
+
+ This is the same, but uses t as the dummy-variable:
+ plot [t = -10 :30] sin(pi*t)/(pi*t)
+
+ This sets both the x and y ranges:
+ plot [-pi:pi] [-3:3] tan(x), 1/x
+
+ This sets only the y range, and turns off autoscaling on both axes:
+ plot [ ] [-2:sin(5)*-8] sin(x)**besj0(x)
+
+ This sets xmax and ymin only:
+ plot [:200] [-pi:] exp(sin(x))
+
+ This sets the x range for a timeseries:
+ set timefmt "%d/%m/%y %H:%M"
+ plot ["1/6/93 12:00":"5/6/93 12:00"] 'timedata.dat'
+
+3 title
+?commands plot title
+?commands splot title
+?plot title
+?splot title
+ A line title for each function and data set appears in the key, accompanied
+ by a sample of the line and/or symbol used to represent it. It can be
+ changed by using the `title` option.
+
+ Syntax:
+ title "<title>" | notitle ["<ignored title>"]
+
+ where <title> is the new title of the line and must be enclosed in quotes.
+ The quotes will not be shown in the key. A special character may be given as
+ a backslash followed by its octal value ("\345"). The tab character "\t" is
+ understood. Note that backslash processing occurs only for strings enclosed
+ in double quotes---use single quotes to prevent such processing. The newline
+ character "\n" is not processed in key entries in either type of string.
+
+ The line title and sample can be omitted from the key by using the keyword
+ `notitle`. A null title (`title ''`) is equivalent to `notitle`. If only
+ the sample is wanted, use one or more blanks (`title ' '`). If `notitle`
+ is followed by a string this string is ignored.
+
+ If `key autotitles` is set (which is the default) and neither `title` nor
+ `notitle` are specified the line title is the function name or the file name as
+ it appears on the `plot` command. If it is a file name, any datafile modifiers
+ specified will be included in the default title.
+
+ The layout of the key itself (position, title justification, etc.) can be
+ controlled by `set key`. Please see `set key` for details.
+
+ Examples:
+
+ This plots y=x with the title 'x':
+ plot x
+
+ This plots x squared with title "x^2" and file "data.1" with title
+ "measured data":
+ plot x**2 title "x^2", 'data.1' t "measured data"
+
+ This puts an untitled circular border around a polar graph:
+ set polar; plot my_function(t), 1 notitle
+3 with
+?commands plot with
+?commands splot with
+?commands plot style
+?commands splot style
+?plot with
+?plot style
+?splot with
+?splot style
+?style
+?with
+ Functions and data may be displayed in one of a large number of styles.
+ The `with` keyword provides the means of selection.
+
+ Syntax:
+ with <style> { {linestyle | ls <line_style>}
+ | {{linetype | lt <line_type>}
+ {linewidth | lw <line_width>}
+ {linecolor | lc <colorspec>}
+ {pointtype | pt <point_type>}
+ {pointsize | ps <point_size>}
+ {fill | fs <fillstyle>}
+ {nohidden3d | nocontours}
+ {palette}}
+ }
+
+ where <style> is either `lines`, `points`, `linespoints`, `impulses`,
+ `dots`, `steps`, `fsteps`, `histeps`, `errorbars`, `labels`, `xerrorbars`,
+ `yerrorbars`, `xyerrorbars`, `errorlines`, `xerrorlines`, `yerrorlines`,
+ `xyerrorlines`, `boxes`, `histograms`, `filledcurves`, `boxerrorbars`,
+ `boxxyerrorbars`, `financebars`, `candlesticks`, `vectors`, `image`,
+ `rgbimage` or `pm3d`. Some of these styles require additional information.
+ See `plotting styles` for details of each style. `fill` is relevant only
+ to certain 2D plots (currently `boxes` `boxxyerrorbars` and `candlesticks`).
+ Note that `filledcurves` and `pm3d` can take an additional option not
+ listed above (the latter only when used in the `splot` command)---see
+ their help or examples below for more details.
+
+ Default styles are chosen with the `set style function` and `set style data`
+ commands.
+
+ By default, each function and data file will use a different line type and
+ point type, up to the maximum number of available types. All terminal
+ drivers support at least six different point types, and re-use them, in
+ order, if more are required. The LaTeX driver supplies an additional six
+ point types (all variants of a circle), and thus will only repeat after 12
+ curves are plotted with points. The PostScript drivers (`postscript`)
+ supplies a total of 64.
+
+ If you wish to choose the line or point type for a single plot, <line_type>
+ and <point_type> may be specified. These are positive integer constants (or
+ expressions) that specify the line type and point type to be used for the
+ plot. Use `test` to display the types available for your terminal.
+
+ You may also scale the line width and point size for a plot by using
+ <line_width> and <point_size>, which are specified relative to the default
+ values for each terminal. The pointsize may also be altered
+ globally---see `set pointsize` for details. But note that both <point_size>
+ as set here and as set by `set pointsize` multiply the default point
+ size---their effects are not cumulative. That is,
+ `set pointsize 2; plot x w p ps 3` will use points three times default size,
+ not six.
+
+ It is also possible to specify `pointsize variable` either as part of a
+ line style or for an individual plot. In this case one extra column of input
+ is required, i.e. 3 columns for a 2D plot and 4 columns for a 3D splot. The
+ size of each individual point is determined by multiplying the global
+ pointsize by the value read from the data file.
+
+ If you have defined specific line type/width and point type/size combinations
+ with `set style line`, one of these may be selected by setting <line_style> to
+ the index of the desired style.
+
+ If gnuplot was built with `pm3d` support, the special keyword `palette` is
+ allowed for smooth color change of lines, points and dots in `splots`. The
+ color is chosen from a smooth palette which was set previously with the
+ command `set palette`. The color value corresponds to the z-value of the
+ point coordinates or to the color coordinate if specified by the 4th parameter
+ in `using`. Both 2d and 3d plots (`plot` and `splot` commands) can use palette
+ colors as specified by either their fractional value or the corresponding value
+ mapped to the colorbox range. A palette color value can also be read from an
+ explicitly specified column in the `using` specifier.
+ Z value. See `colors`, `set palette`, `linetype`.
+
+ The keyword `nohidden3d` applies only to plots made with the `splot` command.
+ Normally the global option `set hidden3d` applies to all plots in the graph.
+ You can attach the `nohidden3d` option to any individual plots that you want
+ to exclude from the hidden3d processing. The individual elements other than
+ surfaces (i.e. lines, dots, labels, ...) of a plot marked `nohidden3d` will all
+ be drawn, even if they would normally be obscured by other plot elements.
+
+ Similarly, the keyword `nocontours` will turn off contouring for an individual
+ plot even if the global property "set contour" is active.
+
+ The keywords may be abbreviated as indicated.
+
+ Note that the `linewidth`, `pointsize` and `palette` options are not supported
+ by all terminals.
+
+ Examples:
+
+ This plots sin(x) with impulses:
+ plot sin(x) with impulses
+
+ This plots x with points, x**2 with the default:
+ plot x w points, x**2
+
+ This plots tan(x) with the default function style, file "data.1" with lines:
+ plot [ ] [-2:5] tan(x), 'data.1' with l
+
+ This plots "leastsq.dat" with impulses:
+ plot 'leastsq.dat' w i
+
+ This plots the data file "population" with boxes:
+ plot 'population' with boxes
+
+ This plots "exper.dat" with errorbars and lines connecting the points
+ (errorbars require three or four columns):
+ plot 'exper.dat' w lines, 'exper.dat' notitle w errorbars
+
+ Another way to plot "exper.dat" with errorlines (errorbars require three
+ or four columns):
+ plot 'exper.dat' w errorlines
+
+ This plots sin(x) and cos(x) with linespoints, using the same line type but
+ different point types:
+ plot sin(x) with linesp lt 1 pt 3, cos(x) with linesp lt 1 pt 4
+
+ This plots file "data" with points of type 3 and twice usual size:
+ plot 'data' with points pointtype 3 pointsize 2
+
+ This plots file "data" with variable pointsize read from column 4
+ plot 'data' using 1:2:4 with points pt 5 pointsize variable
+
+ This plots two data sets with lines differing only by weight:
+ plot 'd1' t "good" w l lt 2 lw 3, 'd2' t "bad" w l lt 2 lw 1
+
+ This plots filled curve of x*x and a color stripe:
+ plot x*x with filledcurve closed, 40 with filledcurve y1=10
+
+ This plots x*x and a color box:
+ plot x*x, (x>=-5 && x<=5 ? 40 : 1/0) with filledcurve y1=10 lt 8
+
+ This plots a surface with color lines:
+ splot x*x-y*y with line palette
+
+ This plots two color surfaces at different altitudes:
+ splot x*x-y*y with pm3d, x*x+y*y with pm3d at t
+
+2 print
+?commands print
+?print
+ The `print` command prints the value of <expression> to the screen. It is
+ synonymous with `pause 0`. <expression> may be anything that `gnuplot` can
+ evaluate that produces a number, or it can be a string.
+
+ Syntax:
+ print <expression> {, <expression>, ...}
+
+ See `expressions`. The output file can be set with `set print`.
+2 pwd
+?commands pwd
+?pwd
+ The `pwd` command prints the name of the working directory to the screen.
+2 quit
+?commands quit
+?quit
+ The `exit` and `quit` commands and END-OF-FILE character will exit `gnuplot`.
+ Each of these commands will clear the output device (as does the `clear`
+ command) before exiting.
+2 raise
+?commands raise
+?raise
+ Syntax:
+ raise {plot_window_nb}
+
+ The `raise` command raises (opposite to `lower`) plot window(s) associated
+ with the interactive terminal of your gnuplot session, i.e. `pm`, `win`, `wxt`
+ or `x11`. It puts the plot window to front (top) in the z-order windows stack
+ of the window manager of your desktop.
+
+ As `x11` and `wxt` support multiple plot windows, then by default they raise
+ these windows in descending order of most recently created on top to the least
+ recently created on bottom. If a plot number is supplied as an optional
+ parameter, only the associated plot window will be raised if it exists.
+
+ The optional parameter is ignored for single plot-windows terminal, i.e. `pm`
+ and `win`.
+
+ If the window is not raised under X11, then (1) they don't run in the same
+ X11 session (telnet or ssh session, for example), or (2) raising is blocked
+ by your window manager. On KDE, you may like to go to the KDE Control Center
+ => Desktop => Window Behaviour => Advanced and set the "Focus stealing
+ prevention level" to None (default is Low).
+2 replot
+?commands replot
+?replot
+ The `replot` command without arguments repeats the last `plot` or `splot`
+ command. This can be useful for viewing a plot with different `set` options,
+ or when generating the same plot for several devices.
+
+ Arguments specified after a `replot` command will be added onto the last
+ `plot` or `splot` command (with an implied ',' separator) before it is
+ repeated. `replot` accepts the same arguments as the `plot` and `splot`
+ commands except that ranges cannot be specified. Thus you can use `replot`
+ to plot a function against the second axes if the previous command was `plot`
+ but not if it was `splot`.
+
+ N.B.---use of
+
+ plot '-' ; ... ; replot
+
+ is not recommended. `gnuplot` does not store the inline data internally, so
+ since `replot` appends new information to the previous `plot` and then
+ executes the modified command, the `'-'` from the initial `plot` will expect
+ to read inline data again.
+
+ Note that `replot` does not work in `multiplot` mode, since it reproduces
+ only the last plot rather than the entire screen.
+
+ See also `command-line-editing` for ways to edit the last `plot` (`splot`)
+ command.
+
+ See also `show plot` to show the whole current plotting command, and the
+ possibility to copy it into the `history`.
+2 reread
+?commands reread
+?reread
+ The `reread` command causes the current `gnuplot` command file, as specified
+ by a `load` command or on the command line, to be reset to its starting
+ point before further commands are read from it. This essentially implements
+ an endless loop of the commands from the beginning of the command file to
+ the `reread` command. (But this is not necessarily a disaster---`reread` can
+ be very useful when used in conjunction with `if`. See `if` for details.)
+ The `reread` command has no effect if input from standard input.
+
+ Examples:
+
+ Suppose the file "looper" contains the commands
+ a=a+1
+ plot sin(x*a)
+ pause -1
+ if(a<5) reread
+ and from within `gnuplot` you submit the commands
+ a=0
+ load 'looper'
+ The result will be five plots (separated by the `pause` message).
+
+ Suppose the file "data" contains six columns of numbers with a total yrange
+ from 0 to 10; the first is x and the next are five different functions of x.
+ Suppose also that the file "plotter" contains the commands
+ c_p = c_p+1
+ plot "$0" using 1:c_p with lines linetype c_p
+ if(c_p < n_p) reread
+ and from within `gnuplot` you submit the commands
+ n_p=6
+ c_p=1
+ unset key
+ set yrange [0:10]
+ set multiplot
+ call 'plotter' 'data'
+ unset multiplot
+ The result is a single graph consisting of five plots. The yrange must be
+ set explicitly to guarantee that the five separate graphs (drawn on top of
+ each other in multiplot mode) will have exactly the same axes. The linetype
+ must be specified; otherwise all the plots would be drawn with the same type.
+ See animate.dem in demo directory for an animated example.
+
+2 reset
+?commands reset
+?reset
+ The `reset` command causes all graph-related options that can be set with the
+ `set` command to take on their default values. This command is useful, e.g.,
+ to restore the default graph settings at the end of a command file, or to
+ return to a defined state after lots of settings have been changed within a
+ command file. Please refer to the `set` command to see the default values
+ that the various options take.
+
+ The following `set` commands do not change the graph status and are thus left
+ unchanged: the terminal set with `set term`, the output file set with `set
+ output` and directory paths set with `set loadpath` and `set fontpath`.
+2 save
+^ <a name="save set"></a>
+?commands save
+?save
+ The `save` command saves user-defined functions, variables, the `set
+ term` status, all `set` options, or all of these, plus the last `plot`
+ (`splot`) command to the specified file.
+
+ Syntax:
+ save {<option>} '<filename>'
+
+ where <option> is `functions`, `variables`, `terminal` or `set`. If
+ no option is used, `gnuplot` saves functions, variables, `set`
+ options and the last `plot` (`splot`) command.
+
+ `save`d files are written in text format and may be read by the
+ `load` command. For `save` with the `set` option or without any
+ option, the `terminal` choice and the `output` filename are written
+ out as a comment, to get an output file that works in other
+ installations of gnuplot, without changes and without risk of
+ unwillingly overwriting files.
+
+ `save terminal` will write out just the `terminal` status, without
+ the comment marker in front of it. This is mainly useful for
+ switching the `terminal` setting for a short while, and getting back
+ to the previously set terminal, afterwards, by loading the saved
+ `terminal` status. Note that for a single gnuplot session you may
+ rather use the other method of saving and restoring current terminal
+ by the commands `set term push` and `set term pop`, see `set term`.
+
+ The filename must be enclosed in quotes.
+
+ The special filename "-" may be used to `save` commands to standard output.
+ On systems which support a popen function (Unix), the output of save can be
+ piped through an external program by starting the file name with a '|'.
+ This provides a consistent interface to `gnuplot`'s internal settings to
+ programs which communicate with `gnuplot` through a pipe. Please see
+ help for `batch/interactive` for more details.
+
+ Examples:
+ save 'work.gnu'
+ save functions 'func.dat'
+ save var 'var.dat'
+ save set 'options.dat'
+ save term 'myterm.gnu'
+ save '-'
+ save '|grep title >t.gp'
+2 set-show
+?commands set
+?commands show
+?set
+?show
+?show all
+ The `set` command can be used to set _lots_ of options. No screen is
+ drawn, however, until a `plot`, `splot`, or `replot` command is given.
+
+ The `show` command shows their settings; `show all` shows all the
+ settings.
+
+ Options changed using `set` can be returned to the default state by giving the
+ corresponding `unset` command. See also the `reset` command, which returns
+ all settable parameters to default values.
+
+ If a variable contains time/date data, `show` will display it according to
+ the format currently defined by `set timefmt`, even if that was not in effect
+ when the variable was initially defined.
+3 angles
+?commands set angles
+?commands show angles
+?set angles
+?show angles
+?angles
+?commands set angles degrees
+?set angles degrees
+?angles degrees
+?degrees
+ By default, `gnuplot` assumes the independent variable in polar graphs is in
+ units of radians. If `set angles degrees` is specified before `set polar`,
+ then the default range is [0:360] and the independent variable has units of
+ degrees. This is particularly useful for plots of data files. The angle
+ setting also applies to 3-d mapping as set via the `set mapping` command.
+
+ Syntax:
+ set angles {degrees | radians}
+ show angles
+
+ The angle specified in `set grid polar` is also read and displayed in the
+ units specified by `set angles`.
+
+ `set angles` also affects the arguments of the machine-defined functions
+ sin(x), cos(x) and tan(x), and the outputs of asin(x), acos(x), atan(x),
+ atan2(x), and arg(x). It has no effect on the arguments of hyperbolic
+ functions or Bessel functions. However, the output arguments of inverse
+ hyperbolic functions of complex arguments are affected; if these functions
+ are used, `set angles radians` must be in effect to maintain consistency
+ between input and output arguments.
+
+ x={1.0,0.1}
+ set angles radians
+ y=sinh(x)
+ print y #prints {1.16933, 0.154051}
+ print asinh(y) #prints {1.0, 0.1}
+ but
+ set angles degrees
+ y=sinh(x)
+ print y #prints {1.16933, 0.154051}
+ print asinh(y) #prints {57.29578, 5.729578}
+ See also
+^ <a href="http://www.gnuplot.info/demo/poldat.html">
+ poldat.dem: polar plot using `set angles` demo.
+^ </a>
+3 arrow
+?commands set arrow
+?commands unset arrow
+?commands show arrow
+?set arrow
+?unset arrow
+?show arrow
+?arrow
+?noarrow
+ Arbitrary arrows can be placed on a plot using the `set arrow` command.
+
+ Syntax:
+ set arrow {<tag>} {from <position>} {to|rto <position>}
+ { {arrowstyle | as <arrow_style>}
+ | { {nohead | head | backhead | heads}
+ {size <length>,<angle>{,<backangle>}}
+ {filled | empty | nofilled}
+ {front | back}
+ { {linestyle | ls <line_style>}
+ | {linetype | lt <line_type>}
+ {linewidth | lw <line_width} } } }
+
+ unset arrow {<tag>}
+ show arrow {<tag>}
+
+ <tag> is an integer that identifies the arrow. If no tag is given, the
+ lowest unused tag value is assigned automatically. The tag can be used to
+ delete or change a specific arrow. To change any attribute of an existing
+ arrow, use the `set arrow` command with the appropriate tag and specify the
+ parts of the arrow to be changed.
+
+ The <position>s are specified by either x,y or x,y,z, and may be preceded by
+ `first`, `second`, `graph`, `screen`, or `character` to select the coordinate
+ system. Unspecified coordinates default to 0. The end points can be
+ specified in one of five coordinate systems---`first` or `second` axes,
+ `graph`, `screen`, or `character`. See `coordinates` for details. A
+ coordinate system specifier does not carry over from the "from" position to
+ the "to" position. Arrows outside the screen boundaries are permitted but
+ may cause device errors. If the end point is specified by "rto" instead of
+ "to" it is drawn relatively to the start point. For linear axes, `graph`
+ and `screen` coordinates, the distance between the start and the end point
+ corresponds to the given relative coordinate. For logarithmic axes, the
+ relative given coordinate corresponds to the factor of the coordinate
+ between start and end point. Thus, a negative relative value or zero are
+ not allowed for logarithmic axes.
+
+ Specifying `nohead` produces an arrow drawn without a head---a line segment.
+ This gives you yet another way to draw a line segment on the plot. By
+ default, an arrow has a head at its end. Specifying `backhead` draws an arrow
+ head at the start point of the arrow while `heads` draws arrow heads on both
+ ends of the line. Not all terminal types support double-ended arrows.
+
+ Head size can be controlled by `size <length>,<angle>` or
+ `size <length>,<angle>,<backangle>`, where `<length>` defines length of each
+ branch of the arrow head and `<angle>` the angle (in degrees) they make with
+ the arrow. `<Length>` is in x-axis units; this can be changed by `first`,
+ `second`, `graph`, `screen`, or `character` before the <length>; see
+ `coordinates` for details. `<Backangle>` only takes effect when `filled`
+ or `empty` is also used. Then, `<backangle>` is the angle (in degrees) the
+ back branches make with the arrow (in the same direction as `<angle>`).
+ The `fig` terminal has a restricted backangle function. It supports three
+ different angles. There are two thresholds: Below 70 degrees, the arrow head
+ gets an indented back angle. Above 110 degrees, the arrow head has an acute
+ back angle. Between these thresholds, the back line is straight.
+
+ Specifying `filled` produces filled arrow heads (if heads are used).
+ Filling is supported on filled-polygon capable terminals, see help of `pm3d`
+ for their list, otherwise the arrow heads are closed but not filled.
+ The same result (closed but not filled arrow head) is reached by specifying
+ `empty`. Further, filling and outline is obviously not supported on
+ terminals drawing arrows by their own specific routines, like `metafont`,
+ `metapost`, `latex` or `tgif`.
+
+ The line style may be selected from a user-defined list of line styles
+ (see `set style line`) or may be defined here by providing values for
+ <line_type> (an index from the default list of styles) and/or <line_width>
+ (which is a multiplier for the default width).
+
+ Note, however, that if a user-defined line style has been selected, its
+ properties (type and width) cannot be altered merely by issuing another
+ `set arrow` command with the appropriate index and `lt` or `lw`.
+
+ If `front` is given, the arrow is written on top of the graphed data. If
+ `back` is given (the default), the arrow is written underneath the graphed
+ data. Using `front` will prevent an arrow from being obscured by dense data.
+
+ Examples:
+
+ To set an arrow pointing from the origin to (1,2) with user-defined style 5,
+ use:
+ set arrow to 1,2 ls 5
+
+ To set an arrow from bottom left of plotting area to (-5,5,3), and tag the
+ arrow number 3, use:
+ set arrow 3 from graph 0,0 to -5,5,3
+
+ To change the preceding arrow to end at 1,1,1, without an arrow head and
+ double its width, use:
+ set arrow 3 to 1,1,1 nohead lw 2
+
+ To draw a vertical line from the bottom to the top of the graph at x=3, use:
+ set arrow from 3, graph 0 to 3, graph 1 nohead
+
+ To draw a vertical arrow with T-shape ends, use:
+ set arrow 3 from 0,-5 to 0,5 heads size screen 0.1,90
+
+ To draw an arrow relatively to the start point, where the relative distances
+ are given in graph coordinates, use:
+ set arrow from 0,-5 rto graph 0.1,0.1
+
+ To draw an arrow with relative end point in logarithmic x axis, use:
+ set logscale x
+ set arrow from 100,-5 rto 10,10
+ This draws an arrow from 100,-5 to 1000,5. For the logarithmic x axis, the
+ relative coordinate 10 means "factor 10" while for the linear y axis, the
+ relative coordinate 10 means "difference 10".
+
+ To delete arrow number 2, use:
+ unset arrow 2
+
+ To delete all arrows, use:
+ unset arrow
+
+ To show all arrows (in tag order), use:
+ show arrow
+
+^ <a href="http://gnuplot.sourceforge.net/demo/arrowstyle.html">
+ arrows demos.
+^ </a>
+
+3 autoscale
+?commands set autoscale
+?commands unset autoscale
+?commands show autoscale
+?set autoscale
+?unset autoscale
+?show autoscale
+?autoscale
+?noautoscale
+ Autoscaling may be set individually on the x, y or z axis or globally on all
+ axes. The default is to autoscale all axes.
+
+ Syntax:
+ set autoscale {<axes>{|min|max|fixmin|fixmax|fix} | fix | keepfix}
+ unset autoscale {<axes>}
+ show autoscale
+
+ where <axes> is either `x`, `y`, `z`, `cb`, `x2`, `y2` or `xy`. A keyword with
+ `min` or `max` appended (this cannot be done with `xy`) tells `gnuplot` to
+ autoscale just the minimum or maximum of that axis. If no keyword is given,
+ all axes are autoscaled.
+
+ A keyword with `fixmin`, `fixmax` or `fix` appended tells gnuplot to disable
+ extension of the axis range to the next tic mark position, for autoscaled
+ axes using equidistant tics; `set autoscale fix` sets this for all axes.
+ Command `set autoscale keepfix` autoscales all axes while keeping the fix
+ settings.
+
+ When autoscaling, the axis range is automatically computed and the dependent
+ axis (y for a `plot` and z for `splot`) is scaled to include the range of the
+ function or data being plotted.
+
+ If autoscaling of the dependent axis (y or z) is not set, the current y or z
+ range is used.
+
+ Autoscaling the independent variables (x for `plot` and x,y for `splot`) is a
+ request to set the domain to match any data file being plotted. If there are
+ no data files, autoscaling an independent variable has no effect. In other
+ words, in the absence of a data file, functions alone do not affect the x
+ range (or the y range if plotting z = f(x,y)).
+
+ Please see `set xrange` for additional information about ranges.
+
+ The behavior of autoscaling remains consistent in parametric mode, (see
+ `set parametric`). However, there are more dependent variables and hence more
+ control over x, y, and z axis scales. In parametric mode, the independent or
+ dummy variable is t for `plot`s and u,v for `splot`s. `autoscale` in
+ parametric mode, then, controls all ranges (t, u, v, x, y, and z) and allows
+ x, y, and z to be fully autoscaled.
+
+ Autoscaling works the same way for polar mode as it does for parametric mode
+ for `plot`, with the extension that in polar mode `set dummy` can be used to
+ change the independent variable from t (see `set dummy`).
+
+ When tics are displayed on second axes but no plot has been specified for
+ those axes, x2range and y2range are inherited from xrange and yrange. This
+ is done _before_ xrange and yrange are autoextended to a whole number of
+ tics, which can cause unexpected results. You can use the `fixmin`
+ or `fixmax` options to avoid this.
+
+ Examples:
+
+ This sets autoscaling of the y axis (other axes are not affected):
+ set autoscale y
+
+ This sets autoscaling only for the minimum of the y axis (the maximum of the
+ y axis and the other axes are not affected):
+ set autoscale ymin
+
+ This disables extension of the x2 axis tics to the next tic mark,
+ thus keeping the exact range as found in the plotted data and functions:
+ set autoscale x2fixmin
+ set autoscale x2fixmax
+
+ This sets autoscaling of the x and y axes:
+ set autoscale xy
+
+ This sets autoscaling of the x, y, z, x2 and y2 axes:
+ set autoscale
+
+ This disables autoscaling of the x, y, z, x2 and y2 axes:
+ unset autoscale
+
+ This disables autoscaling of the z axis only:
+ unset autoscale z
+4 parametric mode
+?commands set autoscale parametric
+?set autoscale parametric
+?set autoscale t
+ When in parametric mode (`set parametric`), the xrange is as fully scalable
+ as the y range. In other words, in parametric mode the x axis can be
+ automatically scaled to fit the range of the parametric function that is
+ being plotted. Of course, the y axis can also be automatically scaled just
+ as in the non-parametric case. If autoscaling on the x axis is not set, the
+ current x range is used.
+
+ Data files are plotted the same in parametric and non-parametric mode.
+ However, there is a difference in mixed function and data plots: in
+ non-parametric mode with autoscaled x, the x range of the datafile controls
+ the x range of the functions; in parametric mode it has no influence.
+
+ For completeness a last command `set autoscale t` is accepted. However, the
+ effect of this "scaling" is very minor. When `gnuplot` determines that the
+ t range would be empty, it makes a small adjustment if autoscaling is true.
+ Otherwise, `gnuplot` gives an error. Such behavior may, in fact, not be very
+ useful and the command `set autoscale t` is certainly questionable.
+
+ `splot` extends the above ideas as you would expect. If autoscaling is set,
+ then x, y, and z ranges are computed and each axis scaled to fit the
+ resulting data.
+4 polar mode
+?commands set autoscale polar
+?set autoscale polar
+ When in polar mode (`set polar`), the xrange and the yrange are both found
+ from the polar coordinates, and thus they can both be automatically scaled.
+ In other words, in polar mode both the x and y axes can be automatically
+ scaled to fit the ranges of the polar function that is being plotted.
+
+ When plotting functions in polar mode, the rrange may be autoscaled. When
+ plotting data files in polar mode, the trange may also be autoscaled. Note
+ that if the trange is contained within one quadrant, autoscaling will produce
+ a polar plot of only that single quadrant.
+
+ Explicitly setting one or two ranges but not others may lead to unexpected
+ results.
+ See also
+^ <a href="http://www.gnuplot.info/demo/poldat.html">
+ polar demos.
+^ </a>
+3 bars
+?commands set bars
+?commands show bars
+?set bars
+?show bars
+?bars
+ The `set bars` command controls the tics at the ends of error bars,
+ and also the width of the boxes in plot styles candlesticks and
+ financebars.
+
+ Syntax:
+ set bars {small | large | fullwidth | <size>}
+ unset bars
+ show bars
+
+ `small` is a synonym for 0.0, and `large` for 1.0.
+ The default is 1.0 if no size is given.
+
+ The keyword `fullwidth` is relevant only to histograms with errorbars.
+ It sets the width of the errorbar ends to be the same as the width of the
+ associated box in the histogram. It does not change the width of the box
+ itself.
+3 bmargin
+?commands set bmargin
+?set bmargin
+?bmargin
+ The command `set bmargin` sets the size of the bottom margin.
+ Please see `set margin` for details.
+3 border
+?commands set border
+?commands unset border
+?commands show border
+?set border
+?unset border
+?show border
+?border
+?noborder
+ The `set border` and `unset border` commands control the display of the graph
+ borders for the `plot` and `splot` commands. Note that the borders do not
+ necessarily coincide with the axes; with `plot` they often do, but with
+ `splot` they usually do not.
+
+ Syntax:
+ set border {<integer>} {front | back} {linewidth | lw <line_width>}
+ {{linestyle | ls <line_style>} | {linetype | lt <line_type>}}
+ unset border
+ show border
+
+ With a `splot` displayed in an arbitrary orientation, like `set view 56,103`,
+ the four corners of the x-y plane can be referred to as "front", "back",
+ "left" and "right". A similar set of four corners exist for the top surface,
+ of course. Thus the border connecting, say, the back and right corners of the
+ x-y plane is the "bottom right back" border, and the border connecting the top
+ and bottom front corners is the "front vertical". (This nomenclature is
+ defined solely to allow the reader to figure out the table that follows.)
+
+ The borders are encoded in a 12-bit integer: the bottom four bits control the
+ border for `plot` and the sides of the base for `splot`; the next four bits
+ control the verticals in `splot`; the top four bits control the edges on top
+ of the `splot`. In detail, `<integer>` should be the sum of the appropriate
+ entries from the following table:
+
+@start table - first is interactive cleartext form
+ Bit plot splot
+ 1 bottom bottom left front
+ 2 left bottom left back
+ 4 top bottom right front
+ 8 right bottom right back
+ 16 no effect left vertical
+ 32 no effect back vertical
+ 64 no effect right vertical
+ 128 no effect front vertical
+ 256 no effect top left back
+ 512 no effect top right back
+ 1024 no effect top left front
+ 2048 no effect top right front
+#\begin{tabular}{|c|c|c|} \hline
+#\multicolumn{3}{|c|}{Graph Border Encoding} \\ \hline \hline
+#Bit & plot & splot \\ \hline
+#1 & bottom & bottom left front \\
+#2 & left & bottom left back \\
+#4 & top & bottom right front \\
+#8 & right & bottom right back \\
+#16 & no effect & left vertical \\
+#32 & no effect & back vertical \\
+#64 & no effect & right vertical \\
+#128 & no effect & front vertical \\
+#256 & no effect & top left back \\
+#512 & no effect & top right back \\
+#1024 & no effect & top left front \\
+#2048 & no effect & top right front \\
+%c c c .
+%Bit@plot@splot
+%_
+%1@bottom@bottom left front
+%2@left@bottom left back
+%4@top@bottom right front
+%8@right@bottom right back
+%16@no effect@left vertical
+%32@no effect@back vertical
+%64@no effect@right vertical
+%128@no effect@front vertical
+%256@no effect@top left back
+%512@no effect@top right back
+%1024@no effect@top left front
+%2048@no effect@top right front
+@end table
+
+ Various bits or combinations of bits may be added together in the command.
+
+ The default is 31, which is all four sides for `plot`, and base and z axis
+ for `splot`.
+
+ In 2D plots the border is normally drawn on top of all plots elements
+ (`front`). If you want the border to be drawn behind the plot elements,
+ use `set border back`.
+
+ Using the optional <line_style>, <line_type> and <line_width> specifiers, the
+ way the border lines are drawn can be influenced (limited by what the current
+ terminal driver supports).
+
+ For `plot`, tics may be drawn on edges other than bottom and left by enabling
+ the second axes -- see `set xtics` for details.
+
+ If a `splot` draws only on the base, as is the case with "`unset surface; set
+ contour base`", then the verticals and the top are not drawn even if they are
+ specified.
+
+ The `set grid` options 'back', 'front' and 'layerdefault' also
+ control the order in which the border lines are drawn with respect to
+ the output of the plotted data.
+
+ Examples:
+
+ Draw default borders:
+ set border
+
+ Draw only the left and bottom (`plot`) or both front and back bottom left
+ (`splot`) borders:
+ set border 3
+
+ Draw a complete box around a `splot`:
+ set border 4095
+
+ Draw a topless box around a `splot`, omitting the front vertical:
+ set border 127+256+512 # or set border 1023-128
+
+ Draw only the top and right borders for a `plot` and label them as axes:
+ unset xtics; unset ytics; set x2tics; set y2tics; set border 12
+
+3 boxwidth
+?commands set boxwidth
+?commands show boxwidth
+?set boxwidth
+?show boxwidth
+?boxwidth
+ The `set boxwidth` command is used to set the default width of boxes in the
+ `boxes`, `boxerrorbars`, `candlesticks` and `histograms` styles.
+
+ Syntax:
+ set boxwidth {<width>} {absolute|relative}
+ show boxwidth
+
+ By default, adjacent boxes are extended in width until they touch each other.
+ A different default width may be specified using the `set boxwidth` command.
+ `Relative` widths are interpreted as being a fraction of this default width.
+
+ An explicit value for the boxwidth is interpreted as being a number of units
+ along the current x axis (`absolute`) unless the modifier `relative` is given.
+ If the x axis is a log-scale (see `set log`) then the value of boxwidth is
+ truly "absolute" only at x=1; this physical width is maintained everywhere
+ along the axis (i.e. the boxes do not become narrower the value of x
+ increases). If the range spanned by a log scale x axis is far from x=1,
+ some experimentation may be required to find a useful value of boxwidth.
+
+ The default is superseded by explicit width information taken from an extra
+ data column in styles `boxes` or `boxerrorbars`. In a four-column data set,
+ the fourth column will be interpreted as the box width unless the width is set
+ to -2.0, in which case the width will be calculated automatically.
+ See `style boxes` and `style boxerrorbars` for more details.
+
+ To set the box width to automatic use the command
+ set boxwidth
+
+ or, for four-column data,
+ set boxwidth -2
+
+ The same effect can be achieved with the `using` keyword in `plot`:
+ plot 'file' using 1:2:3:4:(-2)
+
+ To set the box width to half of the automatic size use
+ set boxwidth 0.5 relative
+
+ To set the box width to an absolute value of 2 use
+ set boxwidth 2 absolute
+3 clabel
+?commands set clabel
+?commands unset clabel
+?commands show clabel
+?set clabel
+?unset clabel
+?show clabel
+?clabel
+ `gnuplot` will vary the linetype used for each contour level when clabel is
+ set. When this option on (the default), a legend labels each linestyle with
+ the z level it represents. It is not possible at present to separate the
+ contour labels from the surface key.
+
+ Syntax:
+ set clabel {'<format>'}
+ unset clabel
+ show clabel
+
+ The default for the format string is %8.3g, which gives three decimal places.
+ This may produce poor label alignment if the key is altered from its default
+ configuration.
+
+ The first contour linetype, or only contour linetype when clabel is off, is
+ the surface linetype +1; contour points are the same style as surface points.
+
+ See also `set contour`.
+3 clip
+?commands set clip
+?commands unset clip
+?commands show clip
+?set clip
+?unset clip
+?show clip
+?clip
+?noclip
+ `gnuplot` can clip data points and lines that are near the boundaries of a
+ graph.
+
+ Syntax:
+ set clip <clip-type>
+ unset clip <clip-type>
+ show clip
+
+ Three clip types for points and lines are supported by `gnuplot`: `points`,
+ `one`, and `two`. One, two, or all three clip types may be active for a
+ single graph.
+ Note that clipping of color filled quadrangles drawn by `pm3d` maps and
+ surfaces is not controlled by this command, but by `set pm3d clip1in` and
+ `set pm3d clip4in`.
+
+ The `points` clip type forces `gnuplot` to clip (actually, not plot at all)
+ data points that fall within but too close to the boundaries. This is done
+ so that large symbols used for points will not extend outside the boundary
+ lines. Without clipping points near the boundaries, the plot may look bad.
+ Adjusting the x and y ranges may give similar results.
+
+ Setting the `one` clip type causes `gnuplot` to draw a line segment which has
+ only one of its two endpoints within the graph. Only the in-range portion of
+ the line is drawn. The alternative is to not draw any portion of the line
+ segment.
+
+ Some lines may have both endpoints out of range, but pass through the graph.
+ Setting the `two` clip-type allows the visible portion of these lines to be
+ drawn.
+
+ In no case is a line drawn outside the graph.
+
+ The defaults are `noclip points`, `clip one`, and `noclip two`.
+
+ To check the state of all forms of clipping, use
+ show clip
+
+ For backward compatibility with older versions, the following forms are also
+ permitted:
+ set clip
+ unset clip
+
+ `set clip` is synonymous with `set clip points`; `unset clip` turns off all
+ three types of clipping.
+3 cntrparam
+?commands set cntrparam
+?commands show cntrparam
+?set cntrparam
+?show cntrparam
+?cntrparam
+ `set cntrparam` controls the generation of contours and their smoothness for
+ a contour plot. `show contour` displays current settings of `cntrparam` as
+ well as `contour`.
+
+ Syntax:
+ set cntrparam { { linear
+ | cubicspline
+ | bspline
+ | points <n>
+ | order <n>
+ | levels { auto {<n>} | <n>
+ | discrete <z1> {,<z2>{,<z3>...}}
+ | incremental <start>, <incr> {,<end>}
+ }
+ }
+ }
+ show contour
+
+ This command has two functions. First, it sets the values of z for which
+ contour points are to be determined (by linear interpolation between data
+ points or function isosamples.) Second, it controls the way contours are
+ drawn between the points determined to be of equal z. <n> should be an
+ integral constant expression and <z1>, <z2> ... any constant expressions.
+ The parameters are:
+
+ `linear`, `cubicspline`, `bspline`---Controls type of approximation or
+ interpolation. If `linear`, then straight line segments connect points of
+ equal z magnitude. If `cubicspline`, then piecewise-linear contours are
+ interpolated between the same equal z points to form somewhat smoother
+ contours, but which may undulate. If `bspline`, a guaranteed-smoother curve
+ is drawn, which only approximates the position of the points of equal-z.
+
+ `points`---Eventually all drawings are done with piecewise-linear strokes.
+ This number controls the number of line segments used to approximate the
+ `bspline` or `cubicspline` curve. Number of cubicspline or bspline
+ segments (strokes) = `points` * number of linear segments.
+
+ `order`---Order of the bspline approximation to be used. The bigger this
+ order is, the smoother the resulting contour. (Of course, higher order
+ bspline curves will move further away from the original piecewise linear
+ data.) This option is relevant for `bspline` mode only. Allowed values are
+ integers in the range from 2 (linear) to 10.
+
+ `levels`--- Selection of contour levels, controlled by `auto` (default),
+ `discrete`, `incremental`, and <n>, number of contour levels.
+
+ For `auto`, <n> specifies a nominal number of levels; the actual number will
+ be adjusted to give simple labels. If the surface is bounded by zmin and zmax,
+ contours will be generated at integer multiples of dz between zmin and zmax,
+ where dz is 1, 2, or 5 times some power of ten (like the step between two
+ tic marks).
+
+ For `levels discrete`, contours will be generated at z = <z1>, <z2> ... as
+ specified; the number of discrete levels sets the number of contour levels.
+ In `discrete` mode, any `set cntrparam levels <n>` are ignored.
+
+ For `incremental`, contours are generated at values of z beginning at <start>
+ and increasing by <increment>, until the number of contours is reached. <end>
+ is used to determine the number of contour levels, which will be changed by
+ any subsequent `set cntrparam levels <n>`. If the z axis is logarithmic,
+ <increment> will be interpreted as a factor, just like in `set ztics`.
+
+ If the command `set cntrparam` is given without any arguments specified, the
+ defaults are used: linear, 5 points, order 4, 5 auto levels.
+
+ Examples:
+ set cntrparam bspline
+ set cntrparam points 7
+ set cntrparam order 10
+
+ To select levels automatically, 5 if the level increment criteria are met:
+ set cntrparam levels auto 5
+
+ To specify discrete levels at .1, .37, and .9:
+ set cntrparam levels discrete .1,1/exp(1),.9
+
+ To specify levels from 0 to 4 with increment 1:
+ set cntrparam levels incremental 0,1,4
+
+ To set the number of levels to 10 (changing an incremental end or possibly
+ the number of auto levels):
+ set cntrparam levels 10
+
+ To set the start and increment while retaining the number of levels:
+ set cntrparam levels incremental 100,50
+
+ See also `set contour` for control of where the contours are drawn, and
+ `set clabel` for control of the format of the contour labels and linetypes.
+
+ See also
+^ <a href="http://www.gnuplot.info/demo/contours.html">
+ contours demo (contours.dem)
+^ </a>
+ and
+^ <a href="http://www.gnuplot.info/demo/discrete.html">
+ contours with user defined levels demo (discrete.dem).
+^ </a>
+3 color box
+?commands set colorbox
+?commands show colorbox
+?commands unset colorbox
+?set colorbox
+?show colorbox
+?unset colorbox
+?colorbox
+
+ The color scheme, i.e. the gradient of the smooth color with min_z and
+ max_z values of `pm3d`'s `palette`, is drawn in a color box unless `unset
+ colorbox`.
+
+ set colorbox
+ set colorbox {
+ { vertical | horizontal }
+ { default | user }
+ { origin x, y }
+ { size x, y }
+ { front | back }
+ { noborder | bdefault | border [line style] }
+ }
+ show colorbox
+ unset colorbox
+
+ Color box position can be `default` or `user`. If the latter is specified the
+ values as given with the `origin` and `size` subcommands are used. The box
+ can be drawn after (`front`) or before (`back`) the graph or the surface.
+
+ The orientation of the color gradient can be switched by options `vertical`
+ and `horizontal`.
+
+ `origin x, y` and `size x, y` are used only in combination with the `user`
+ option. The x and y values are interpreted as screen coordinates by default,
+ and this is the only legal option for 3D plots. 2D plots, including splot with
+ `set view map`, allow any coordinate system to be specified. Try for example:
+ set colorbox horiz user origin .1,.02 size .8,.04
+ which will draw a horizontal gradient somewhere at the bottom of the graph.
+
+ `border` turns the border on (this is the default). `noborder` turns the border
+ off. If an positive integer argument is given after `border`, it is used as a
+ line style tag which is used for drawing the border, e.g.:
+ set style line 2604 linetype -1 linewidth .4
+ set colorbox border 2604
+ will use line style `2604`, a thin line with the default border color (-1)
+ for drawing the border. `bdefault` (which is the default) will use the default
+ border line style for drawing the border of the color box.
+
+ The axis of the color box is called `cb` and it is controlled by means of the
+ usual axes commands, i.e. `set/unset/show` with `cbrange`, `[m]cbtics`,
+ `format cb`, `grid [m]cb`, `cblabel`, and perhaps even `cbdata`, `[no]cbdtics`,
+ `[no]cbmtics`.
+
+ `set colorbox` without any parameter switches the position to default.
+ `unset colorbox` resets the default parameters for the colorbox and switches
+ the colorbox off.
+
+ See also help for `set pm3d`, `set palette`, `x11 pm3d`, and `set style line`.
+
+3 contour
+?commands set contour
+?commands unset contour
+?commands show contour
+?set contour
+?unset contour
+?show contour
+?contour
+?nocontour
+ `set contour` enables contour drawing for surfaces. This option is available
+ for `splot` only. It requires grid data, see `grid_data` for more details.
+ If contours are desired from non-grid data, `set dgrid3d` can be used to
+ create an appropriate grid.
+
+ Syntax:
+ set contour {base | surface | both}
+ unset contour
+ show contour
+
+ The three options specify where to draw the contours: `base` draws the
+ contours on the grid base where the x/ytics are placed, `surface` draws the
+ contours on the surfaces themselves, and `both` draws the contours on both
+ the base and the surface. If no option is provided, the default is `base`.
+
+ See also `set cntrparam` for the parameters that affect the drawing of
+ contours, and `set clabel` for control of labelling of the contours.
+
+ The surface can be switched off (see `set surface`), giving a contour-only
+ graph. Though it is possible to use `set size` to enlarge the plot to fill
+ the screen, more control over the output format can be obtained by writing
+ the contour information to a file, and rereading it as a 2-d datafile plot:
+
+ unset surface
+ set contour
+ set cntrparam ...
+ set table 'filename'
+ splot ...
+ unset table
+ # contour info now in filename
+ set term <whatever>
+ plot 'filename'
+
+ In order to draw contours, the data should be organized as "grid data". In
+ such a file all the points for a single y-isoline are listed, then all the
+ points for the next y-isoline, and so on. A single blank line (a line
+ containing no characters other than blank spaces and a carriage return and/or
+ a line feed) separates one y-isoline from the next.
+ See also `splot datafile`.
+
+ See also
+^ <a href="http://www.gnuplot.info/demo/contours.html">
+ contours demo (contours.dem)
+^ </a>
+ and
+^ <a href="http://www.gnuplot.info/demo/discrete.html">
+ contours with user defined levels demo (discrete.dem).
+^ </a>
+3 data style
+?DUMMYLABEL set style data
+ This form of the command is deprecated. Please see `set style data`.
+3 datafile
+?set datafile
+?show datafile
+ The `set datafile` command options control interpretation of fields read from
+ input data files by the `plot`, `splot`, and `fit` commands. Four such
+ options are currently implemented.
+4 set datafile fortran
+?set datafile fortran
+?fortran
+ The `set datafile fortran` command enables a special check for values in the
+ input file expressed as Fortran D or Q constants. This extra check slows down
+ the input process, and should only be selected if you do in fact have datafiles
+ containing Fortran D or Q constants. The option can be disabled again using
+ `unset datafile fortran`.
+4 set datafile missing
+?set datafile missing
+?set missing
+?missing
+ The `set datafile missing` command allows you to tell `gnuplot` what character
+ string is used in a data file to denote missing data. Exactly how this missing
+ value will be treated depends on the `using` specifier of the `plot` or `splot`
+ command.
+
+ Syntax:
+ set datafile missing {"<string>"}
+ show datafile missing
+ unset datafile
+
+ Example:
+ # Ignore entries containing IEEE NaN ("Not a Number") code
+ set datafile missing "NaN"
+
+ Example:
+ set datafile missing "?"
+ set style data lines
+ plot '-'
+ 1 10
+ 2 20
+ 3 ?
+ 4 40
+ 5 50
+ e
+ plot '-' using 1:2
+ 1 10
+ 2 20
+ 3 ?
+ 4 40
+ 5 50
+ e
+ plot '-' using 1:($2)
+ 1 10
+ 2 20
+ 3 ?
+ 4 40
+ 5 50
+ e
+
+ The first `plot` will recognize only the first datum in the "3 ?" line. It
+ will use the single-datum-on-a-line convention that the line number is "x"
+ and the datum is "y", so the point will be plotted (in this case erroneously)
+ at (2,3).
+
+ The second `plot` will correctly ignore the middle line. The plotted line
+ will connect the points at (2,20) and (4,40).
+
+ The third `plot` will also correctly ignore the middle line, but the plotted
+ line will not connect the points at (2,20) and (4,40).
+
+ There is no default character for `missing`, but in many cases any
+ non-parsible string of characters found where a numerical value is expected
+ will be treated as missing data.
+
+4 set datafile separator
+?set datafile separator
+?show datafile separator
+?datafile separator
+?separator
+ The command `set datafile separator "<char>"` tells `gnuplot` that data fields
+ in subsequent input files are separated by <char> rather than by whitespace.
+ The most common use is to read in csv (comma-separated value) files written
+ by spreadsheet or database programs. By default data fields are separated by
+ whitespace.
+
+ Syntax:
+ set datafile separator {"<char>" | whitespace}
+
+ Examples:
+ # Input file contains tab-separated fields
+ set datafile separator "\t"
+
+ # Input file contains comma-separated values fields
+ set datafile separator ","
+4 set datafile commentschars
+?set datafile commentschars
+?commentschars
+ The `set datafile commentschars` command allows you to tell `gnuplot` what
+ characters are used in a data file to denote comments. Gnuplot will ignore
+ rest of the line behind the specified characters if either of them is the
+ first non-blank character on the line.
+
+ Syntax:
+ set datafile commentschars {"<string>"}
+ show datafile commentschars
+ unset commentschars
+
+ Default value of the string is "#!" on VMS and "#" otherwise.
+
+ Then, the following line in a data file is completely ignored
+ # 1 2 3 4
+ but the following
+ 1 # 3 4
+ produces rather unexpected plot unless
+ set datafile missing '#'
+ is specified as well.
+
+ Example:
+ set datafile commentschars "#!%"
+4 set datafile binary
+?set datafile binary
+ The `set datafile binary` command is used to set the defaults when reading
+ binary data files. The syntax matches precisely that used for commands
+ `plot` and `splot`. See `binary` for details about <binary list>.
+
+ Syntax:
+ set datafile binary <binary list>
+ show datafile binary
+ show datafile
+ unset datafile
+
+ Examples:
+ set datafile binary filetype=auto
+ set datafile binary array=512x512 format="%uchar"
+3 decimalsign
+?commands set decimalsign
+?commands show decimalsign
+?commands unset decimalsign
+?set decimalsign
+?show decimalsign
+?unset decimalsign
+?decimalsign
+=locale
+ The `set decimalsign` command selects a decimal sign for numbers printed
+ into tic labels or `set label` strings.
+
+ Syntax:
+ set decimalsign {<value> | locale {"<locale>"}}
+ unset decimalsign
+ show decimalsign
+
+ The argument <value> is a string to be used in place of the usual
+ decimal point. Typical choices include the period, '.', and the comma,
+ ',', but others may be useful, too. If you omit the <value> argument,
+ the decimal separator is not modified from the usual default, which is
+ a period. Unsetting decimalsign has the same effect as omitting <value>.
+
+ Example:
+
+ Correct typesetting in most European countries requires:
+ set decimalsign ','
+
+ Please note: If you set an explicit string, this affects only numbers that
+ are printed using gnuplot's gprintf() formatting routine, include axis tics.
+ It does not affect the format expected for input data, and it does not affect
+ numbers printed with the sprintf() formatting routine. To change the behavior
+ of both input and output formatting, instead use the form
+
+ set decimalsign locale
+
+ This instructs the program to use both input and output formats in accordance
+ with the current setting of the LC_ALL, LC_NUMERIC, or LANG environmental
+ variables.
+
+ set decimalsign locale "foo"
+
+ This instructs the program to format all input and output in accordance with
+ locale "foo", which must be installed. If locale "foo" is not found then an
+ error message is printed and the decimal sign setting is unchanged.
+ On linux systems you can get a list of the locales installed on your machine by
+ typing "locale -a". A typical linux locale string is of the form "sl_SI.UTF-8".
+ A typical Windows locale string is of the form "Slovenian_Slovenia.1250" or
+ "slovenian". Please note that interpretation of the locale settings is done by
+ the C library at runtime. Older C libraries may offer only partial support for
+ locale settings such as the thousands grouping separator character.
+
+ set decimalsign locale; set decimalsign "."
+
+ This sets all input and output to use whatever decimal sign is correct for
+ the current locale, but over-rides this with an explicit '.' in numbers
+ formatted using gnuplot's internal gprintf() function.
+3 dgrid3d
+?commands set dgrid3d
+?commands unset dgrid3d
+?commands show dgrid3d
+?set dgrid3d
+?unset dgrid3d
+?show dgrid3d
+?dgrid3d
+?nodgrid3d
+ The `set dgrid3d` command enables, and can set parameters for, non-grid to
+ grid data mapping. See `splot grid_data` for more details about the grid data
+ structure.
+
+ Syntax:
+ set dgrid3d {<row_size>} {,{<col_size>} {,<norm>}}
+ unset dgrid3d
+ show dgrid3d
+
+ By default `dgrid3d` is disabled. When enabled, 3-d data read from a file
+ are always treated as a scattered data set. A grid with dimensions derived
+ from a bounding box of the scattered data and size as specified by the
+ row/col_size parameters is created for plotting and contouring. The grid
+ is equally spaced in x (rows) and in y (columns); the z values are computed
+ as weighted averages of the scattered points' z values.
+
+ The third parameter, norm, controls the weighting: Each data point is
+ weighted inversely by its distance from the grid point raised to the norm
+ power. (Actually, the weights are given by the inverse of dx^norm + dy^norm,
+ where dx and dy are the components of the separation of the grid point from
+ each data point. For some norms that are powers of two, specifically 4, 8,
+ and 16, the computation is optimized by using the Euclidean distance in the
+ weight calculation, (dx^2+dy^2)^norm/2. However, any non-negative integer
+ can be used.)
+
+ The closer the data point is to a grid point, the more effect it has on
+ that grid point and the larger the value of norm the less effect more
+ distant data points have on that grid point.
+
+ The `dgrid3d` option is a simple low pass filter that converts scattered
+ data to a grid data set. More sophisticated approaches to this problem
+ exist and should be used to preprocess the data outside `gnuplot` if this
+ simple solution is found inadequate.
+
+ (The z values are found by weighting all data points, not by interpolating
+ between nearby data points; also edge effects may produce unexpected and/or
+ undesired results. In some cases, small norm values produce a grid point
+ reflecting the average of distant data points rather than a local average,
+ while large values of norm may produce "steps" with several grid points
+ having the same value as the closest data point, rather than making a smooth
+ transition between adjacent data points. Some areas of a grid may be filled
+ by extrapolation, to an arbitrary boundary condition. The variables are
+ not normalized; consequently the units used for x and y will affect the
+ relative weights of points in the x and y directions.)
+
+ Examples:
+ set dgrid3d 10,10,1 # defaults
+ set dgrid3d ,,4
+
+ The first specifies that a grid of size 10 by 10 is to be constructed using
+ a norm value of 1 in the weight computation. The second only modifies the
+ norm, changing it to 4.
+ See also
+^ <a href="http://www.gnuplot.info/demo/scatter.html">
+ scatter.dem: dgrid3d demo.
+^ </a>
+
+3 dummy
+?commands set dummy
+?commands show dummy
+?set dummy
+?show dummy
+?dummy
+ The `set dummy` command changes the default dummy variable names.
+
+ Syntax:
+ set dummy {<dummy-var>} {,<dummy-var>}
+ show dummy
+
+ By default, `gnuplot` assumes that the independent, or "dummy", variable for
+ the `plot` command is "t" if in parametric or polar mode, or "x" otherwise.
+ Similarly the independent variables for the `splot` command are "u" and "v"
+ in parametric mode (`splot` cannot be used in polar mode), or "x" and "y"
+ otherwise.
+
+ It may be more convenient to call a dummy variable by a more physically
+ meaningful or conventional name. For example, when plotting time functions:
+
+ set dummy t
+ plot sin(t), cos(t)
+
+ At least one dummy variable must be set on the command; `set dummy` by itself
+ will generate an error message.
+
+ Examples:
+ set dummy u,v
+ set dummy ,s
+
+ The second example sets the second variable to s.
+3 encoding
+?commands set encoding
+?commands show encoding
+?set encoding
+?show encoding
+?encoding
+?encodings
+ The `set encoding` command selects a character encoding.
+ Syntax:
+ set encoding {<value>}
+ show encoding
+
+ Valid values are
+ default - tells a terminal to use its default encoding
+ iso_8859_1 - the most common Western European font used by many
+ Unix workstations and by MS-Windows. This encoding is
+ known in the PostScript world as 'ISO-Latin1'.
+ iso_8859_2 - used in Central and Eastern Europe
+ iso_8859_15 - a variant of iso_8859_1 that includes the Euro symbol
+ koi8r - popular Unix cyrillic encoding
+ koi8u - ukrainian Unix cyrillic encoding
+ cp437 - codepage for MS-DOS
+ cp850 - codepage for OS/2, Western Europe
+ cp852 - codepage for OS/2, Central and Eastern Europe
+ cp1250 - codepage for MS Windows, Central and Eastern Europe
+
+ Generally you must set the encoding before setting the terminal type.
+ Note that encoding is not supported by all terminal drivers and that
+ the device must be able to produce the desired non-standard characters.
+ The PostScript, X11 and wxt terminals support all encodings. OS/2 Presentation
+ Manager switches automatically to codepage 912 for `iso_8859_2`.
+3 fit
+?commands set fit
+?commands show fit
+?set fit
+?show fit
+ The `fit` setting defines where the `fit` command writes its output.
+ If this option was built into your version of gnuplot, it also controls
+ whether parameter errors from the fit will be written into variables.
+
+ Syntax:
+ set fit {logfile {"<filename>"}} {{no}errorvariables}
+ unset fit
+ show fit
+
+ The <filename> argument must be enclosed in single or double quotes.
+
+ If no filename is given or `unset fit` is used the log file is
+ reset to its default value "fit.log" or the value of the environmental
+ variable `FIT_LOG`.
+
+ Users of DOS-like platforms should note that the \ character has
+ special significance in double-quoted strings, so single-quotes
+ should be used for filenames in different directories, or you have
+ to write \\ for each \. Or you can just use forward slashes,
+ even though this is DOS.
+
+ If the given logfile name ends with a / or \, it is interpreted to be
+ a directory name, and the actual filename will be "fit.log" in that
+ directory.
+
+ If the `errorvariables` option is turned on, the error of each fitted
+ parameter computed by `fit` will be copied to a user-defined variable
+ whose name is formed by appending "_err" to the name of the parameter
+ itself. This is useful mainly to put the parameter and its error onto
+ a plot of the data and the fitted function, for reference, as in:
+
+ set fit errorvariables
+ fit f(x) 'datafile' using 1:2 via a, b
+ print "error of a is:", a_err
+ set label 'a=%6.2f', a, '+/- %6.2f', a_err
+ plot 'datafile' using 1:2, f(x)
+3 fontpath
+?commands set fontpath
+?commands show fontpath
+?set fontpath
+?show fontpath
+?fontpath
+ The `fontpath` setting defines additional locations for font files
+ searched when including font files. Currently only the postscript terminal
+ supports `fontpath`. If a file cannot be found in the current directory,
+ the directories in `fontpath` are tried. Further documentation concerning
+ the supported file formats is included in the `terminal postscript` section
+ of the documentation.
+
+ Syntax:
+ set fontpath {"pathlist1" {"pathlist2"...}}
+ show fontpath
+
+ Path names may be entered as single directory names, or as a list of
+ path names separated by a platform-specific path separator, eg. colon
+ (':') on Unix, semicolon (';') on DOS/Windows/OS/2/Amiga platforms.
+ The `show fontpath`, `save` and `save set` commands replace the
+ platform-specific separator with a space character (' ') for maximum
+ portability. If a directory name ends with an exclamation mark ('!') also
+ the subdirectories of this directory are searched for font files.
+
+ If the environmental variable GNUPLOT_FONTPATH is set, its contents are
+ appended to `fontpath`. If it is not set, a system dependent default value
+ is used. It is set by testing several directories for existence when using
+ the fontpath the first time. Thus, the first call of `set fontpath`,
+ `show fontpath`, `save fontpath`, `plot`, or `splot` with embedded font
+ files takes a little more time. If you want to save this time you may
+ set the environmental variable GNUPLOT_FONTPATH since probing is switched
+ off, then. You can find out which is the default fontpath by using
+ `show fontpath`.
+
+ However, `show fontpath` prints the contents of user defined fontpath and
+ system fontpath separately. Also, the `save` and `save set` commands save
+ only the user specified parts of `fontpath`, for portability reasons.
+
+ Many other terminal drivers access TrueType fonts via the gd library.
+ For these drivers the font search path is controlled by the environmental
+ variable GDFONTPATH.
+3 format
+?commands set format
+?commands show format
+?set format
+?show format
+?format
+?format cb
+ The format of the tic-mark labels can be set with the `set format` command
+ or with the `set tics format` or individual `set {axis}tics format` commands.
+
+ Syntax:
+ set format {<axes>} {"<format-string>"}
+ set format {<axes>} {'<format-string>'}
+ show format
+
+ where <axes> is either `x`, `y`, `xy`, `x2`, `y2`, `z`, `cb` or
+ nothing (which refers to all axes at once). The length of the string
+ representing a tic mark (after formatting with 'printf') is restricted
+ to 100 characters. If the format string is omitted, the format will
+ be returned to the default "% g". For LaTeX users, the format "$%g$"
+ is often desirable. If the empty string "" is used, no label will be
+ plotted with each tic, though the tic mark will still be plotted. To
+ eliminate all tic marks, use `unset xtics` or `unset ytics`.
+
+ Newline (\n) is accepted in the format string. Use double-quotes rather than
+ single-quotes to enable such interpretation. See also `syntax`.
+
+ The default format for both axes is "% g", but other formats such as "%.2f" or
+ "%3.0em" are often desirable. Anything accepted by 'printf' when given a
+ double precision number, and accepted by the terminal, will work. Some other
+ options have been added. If the format string looks like a floating point
+ format, then `gnuplot` tries to construct a reasonable format.
+
+ Characters not preceded by "%" are printed verbatim. Thus you can include
+ spaces and labels in your format string, such as "%g m", which will put " m"
+ after each number. If you want "%" itself, double it: "%g %%".
+
+ See also `set xtics` for more information about tic labels, and
+ `set decimalsign` for how to use non-default decimal separators in numbers
+ printed this way.
+ See also
+^ <a href="http://www.gnuplot.info/demo/electron.html">
+ electron demo (electron.dem).
+^ </a>
+4 gprintf
+?gprintf
+ The string function gprintf("format",x) uses gnuplot's own format specifiers,
+ as do the gnuplot commands `set format`, `set timestamp`, and others. These
+ format specifiers are not the same as those used by the standard C-language
+ routine sprintf(). Gnuplot also provides an sprintf("format",x,...) routine
+ if you prefer. For a list of gnuplot's format options, see `format specifiers`.
+4 format specifiers
+?commands set format specifiers
+?set format specifiers
+?format specifiers
+?format_specifiers
+ The acceptable formats (if not in time/date mode) are:
+
+@start table - first is interactive cleartext form
+ Format Explanation
+ %f floating point notation
+ %e or %E exponential notation; an "e" or "E" before the power
+ %g or %G the shorter of %e (or %E) and %f
+ %x or %X hex
+ %o or %O octal
+ %t mantissa to base 10
+ %l mantissa to base of current logscale
+ %s mantissa to base of current logscale; scientific power
+ %T power to base 10
+ %L power to base of current logscale
+ %S scientific power
+ %c character replacement for scientific power
+ %P multiple of pi
+#\begin{tabular}{|cl|} \hline
+#\multicolumn{2}{|c|}{Tic-mark label numerical format specifiers}\\
+#\hline \hline
+#Format & Explanation \\ \hline
+#\verb@%f@ & floating point notation \\
+#\verb@%e@ or \verb@%E@ & exponential notation; an "e" or "E" before the power \\
+#\verb@%g@ or \verb@%G@ & the shorter of \verb@%e@ (or \verb@%E@) and \verb@%f@ \\
+#\verb@%x@ or \verb@%X@ & hex \\
+#\verb@%o@ or \verb@%O@ & octal \\
+#\verb@%t@ & mantissa to base 10 \\
+#\verb@%l@ & mantissa to base of current logscale \\
+#\verb@%s@ & mantissa to base of current logscale; scientific power \\
+#\verb@%T@ & power to base 10 \\
+#\verb@%L@ & power to base of current logscale \\
+#\verb@%S@ & scientific power \\
+#\verb@%c@ & character replacement for scientific power \\
+#\verb@%P@ & multiple of pi \\
+%c l .
+%Format@Explanation
+%_
+%%f@floating point notation
+%%e or %E@exponential notation; an "e" or "E" before the power
+%%g or %G@the shorter of %e (or %E) and %f
+%%x or %X@hex
+%%o or %O@octal
+%%t@mantissa to base 10
+%%l@mantissa to base of current logscale
+%%s@mantissa to base of current logscale; scientific power
+%%T@power to base 10
+%%L@power to base of current logscale
+%%S@scientific power
+%%c@character replacement for scientific power
+%%P@multiple of pi
+%_
+@end table
+
+ A 'scientific' power is one such that the exponent is a multiple of three.
+ Character replacement of scientific powers (`"%c"`) has been implemented
+ for powers in the range -18 to +18. For numbers outside of this range the
+ format reverts to exponential.
+
+ Other acceptable modifiers (which come after the "%" but before the format
+ specifier) are "-", which left-justifies the number; "+", which forces all
+ numbers to be explicitly signed; " " (a space), which makes positive numbers
+ have a space in front of them where negative numbers have "-";
+ "#", which places a decimal point after
+ floats that have only zeroes following the decimal point; a positive integer,
+ which defines the field width; "0" (the digit, not the letter) immediately
+ preceding the field width, which indicates that leading zeroes are to be used
+ instead of leading blanks; and a decimal point followed by a non-negative
+ integer, which defines the precision (the minimum number of digits of an
+ integer, or the number of digits following the decimal point of a float).
+
+ Some systems may not support all of these modifiers but may also support
+ others; in case of doubt, check the appropriate documentation and
+ then experiment.
+
+ Examples:
+ set format y "%t"; set ytics (5,10) # "5.0" and "1.0"
+ set format y "%s"; set ytics (500,1000) # "500" and "1.0"
+ set format y "%+-12.3f"; set ytics(12345) # "+12345.000 "
+ set format y "%.2t*10^%+03T"; set ytic(12345)# "1.23*10^+04"
+ set format y "%s*10^{%S}"; set ytic(12345) # "12.345*10^{3}"
+ set format y "%s %cg"; set ytic(12345) # "12.345 kg"
+ set format y "%.0P pi"; set ytic(6.283185) # "2 pi"
+ set format y "%.0f%%"; set ytic(50) # "50%"
+
+ set log y 2; set format y '%l'; set ytics (1,2,3)
+ #displays "1.0", "1.0" and "1.5" (since 3 is 1.5 * 2^1)
+
+ There are some problem cases that arise when numbers like 9.999 are printed
+ with a format that requires both rounding and a power.
+
+ If the data type for the axis is time/date, the format string must contain
+ valid codes for the 'strftime' function (outside of `gnuplot`, type "man
+ strftime"). See `set timefmt` for a list of the allowed input format codes.
+4 time/date specifiers
+?commands set format date_specifiers
+?commands set format time_specifiers
+?set format date_specifiers
+?set format time_specifiers
+?set date_specifiers
+?set time_specifiers
+?date_specifiers
+?time_specifiers
+ In time/date mode, the acceptable formats are:
+
+@start table - first is interactive cleartext form
+ Format Explanation
+ %a abbreviated name of day of the week
+ %A full name of day of the week
+ %b or %h abbreviated name of the month
+ %B full name of the month
+ %d day of the month, 01--31
+ %D shorthand for "%m/%d/%y" (only output)
+ %F shorthand for "%Y-%m-%d" (only output)
+ %k hour, 0--23 (one or two digits)
+ %H hour, 00--23 (always two digits)
+ %l hour, 1--12 (one or two digits)
+ %I hour, 01--12 (always two digits)
+ %j day of the year, 1--366
+ %m month, 01--12
+ %M minute, 0--60
+ %p "am" or "pm"
+ %r shorthand for "%I:%M:%S %p" (only output)
+ %R shorthand for "%H:%M" (only output)
+ %S second, 0--60
+ %T shorthand for "%H:%M:%S" (only output)
+ %U week of the year (week starts on Sunday)
+ %w day of the week, 0--6 (Sunday = 0)
+ %W week of the year (week starts on Monday)
+ %y year, 0-99
+ %Y year, 4-digit
+#\begin{tabular}{|cl|} \hline
+#\multicolumn{2}{|c|}{Tic-mark label Date/Time Format Specifiers}\\
+#\hline \hline
+#Format & Explanation \\ \hline
+#\verb@%a@ & abbreviated name of day of the week \\
+#\verb@%A@ & full name of day of the week \\
+#\verb@%b@ or \verb@%h@ & abbreviated name of the month \\
+#\verb@%B@ & full name of the month \\
+#\verb@%d@ & day of the month, 1--31 \\
+#\verb@%D@ & shorthand for \verb@"%m/%d/%y"@ (only output) \\
+#\verb@%F@ & shorthand for \verb@"%Y-%m-%d"@ (only output) \\
+#\verb@%k@ & hour, 0--23 (one or two digits)\\
+#\verb@%H@ & hour, 00--23 (always two digits)\\
+#\verb@%l@ & hour, 1--12 (one or two digits)\\
+#\verb@%I@ & hour, 01--12 (always two digits)\\
+#\verb@%j@ & day of the year, 1--366 \\
+#\verb@%m@ & month, 1--12 \\
+#\verb@%M@ & minute, 0--60 \\
+#\verb@%p@ & "am" or "pm" \\
+#\verb@%r@ & shorthand for \verb@"%I:%M:%S %p"@ (only output)\\
+#\verb@%R@ & shorthand for \verb@%H:%M"@ (only output)\\
+#\verb@%S@ & second, 0--60 \\
+#\verb@%T@ & shorthand for \verb@"%H:%M:%S"@ (only output)\\
+#\verb@%U@ & week of the year (week starts on Sunday) \\
+#\verb@%w@ & day of the week, 0--6 (Sunday = 0) \\
+#\verb@%W@ & week of the year (week starts on Monday) \\
+#\verb@%y@ & year, 0-99 \\
+#\verb@%Y@ & year, 4-digit \\
+%c l .
+%Format@Explanation
+%_
+%%a@abbreviated name of day of the week
+%%A@full name of day of the week
+%%b or %h@abbreviated name of the month
+%%B@full name of the month
+%%d@day of the month, 1--31
+%%D@shorthand for "%m/%d/%y" (only output)
+%%F@shorthand for "%Y-%m-%d" (only output)
+%%k@hour, 0--23 (one or two digits)
+%%H@hour, 00--23 (always two digits)
+%%l@hour, 1--12 (one or two digits)
+%%I@hour, 01--12 (always two digits)
+%%j@day of the year, 1--366
+%%m@month, 1--12
+%%M@minute, 0--60
+%%p@"am" or "pm"
+%%r@shorthand for "%I:%M:%S %p" (only output)
+%%R@shorthand for %H:%M" (only output)
+%%S@second, 0--60
+%%T@shorthand for "%H:%M:%S" (only output)
+%%U@week of the year (week starts on Sunday)
+%%w@day of the week, 0--6 (Sunday = 0)
+%%W@week of the year (week starts on Monday)
+%%y@year, 0-99
+%%Y@year, 4-digit
+%_
+@end table
+
+ Except for the non-numerical formats, these may be preceded by a "0" ("zero",
+ not "oh") to pad the field length with leading zeroes, and a positive digit,
+ to define the minimum field width (which will be overridden if the specified
+ width is not large enough to contain the number). There is a 24-character
+ limit to the length of the printed text; longer strings will be truncated.
+
+ Examples:
+
+ Suppose the text is "76/12/25 23:11:11". Then
+ set format x # defaults to "12/25/76" \n "23:11"
+ set format x "%A, %d %b %Y" # "Saturday, 25 Dec 1976"
+ set format x "%r %D" # "11:11:11 pm 12/25/76"
+
+ Suppose the text is "98/07/06 05:04:03". Then
+ set format x "%1y/%2m/%3d %01H:%02M:%03S" # "98/ 7/ 6 5:04:003"
+3 function style
+ This form of the command is deprecated. Please see `set style function`.
+3 functions
+?commands show functions
+?show functions
+ The `show functions` command lists all user-defined functions and their
+ definitions.
+
+ Syntax:
+ show functions
+
+ For information about the definition and usage of functions in `gnuplot`,
+ please see `expressions`.
+ See also
+^ <a href="http://www.gnuplot.info/demo/spline.html">
+ splines as user defined functions (spline.dem)
+^ </a>
+ and
+^ <a href="http://www.gnuplot.info/demo/airfoil.html">
+ use of functions and complex variables for airfoils (airfoil.dem).
+^ </a>
+3 grid
+?commands set grid
+?commands unset grid
+?commands show grid
+?set grid
+?unset grid
+?show grid
+?grid
+?nogrid
+ The `set grid` command allows grid lines to be drawn on the plot.
+
+ Syntax:
+ set grid {{no}{m}xtics} {{no}{m}ytics} {{no}{m}ztics}
+ {{no}{m}x2tics} {{no}{m}y2tics}
+ {{no}{m}cbtics}
+ {polar {<angle>}}
+ {layerdefault | front | back}
+ { {linestyle <major_linestyle>}
+ | {linetype | lt <major_linetype>}
+ {linewidth | lw <major_linewidth>}
+ { , {linestyle | ls <minor_linestyle>}
+ | {linetype | lt <minor_linetype>}
+ {linewidth | lw <minor_linewidth>} } }
+ unset grid
+ show grid
+
+ The grid can be enabled and disabled for the major and/or minor tic
+ marks on any axis, and the linetype and linewidth can be specified
+ for major and minor grid lines, also via a predefined linestyle, as
+ far as the active terminal driver supports this.
+
+ Additionally, a polar grid can be selected for 2-d plots---circles are drawn
+ to intersect the selected tics, and radial lines are drawn at definable
+ intervals. (The interval is given in degrees or radians, depending on the
+ `set angles` setting.) Note that a polar grid is no longer automatically
+ generated in polar mode.
+
+ The pertinent tics must be enabled before `set grid` can draw them; `gnuplot`
+ will quietly ignore instructions to draw grid lines at non-existent tics, but
+ they will appear if the tics are subsequently enabled.
+
+ If no linetype is specified for the minor gridlines, the same linetype as the
+ major gridlines is used. The default polar angle is 30 degrees.
+
+ If `front` is given, the grid is drawn on top of the graphed data. If
+ `back` is given, the grid is drawn underneath the graphed data. Using
+ `front` will prevent the grid from being obscured by dense data. The
+ default setup, `layerdefault`, is equivalent to `back` for 2d plots.
+ In 3D plots the default is to split up the grid and the graph box into
+ two layers: one behind, the other in front of the plotted data and
+ functions. Since `hidden3d` mode does its own sorting, it ignores
+ all grid drawing order options and passes the grid lines through the
+ hidden line removal machinery instead. These options actually affect
+ not only the grid, but also the lines output by `set border` and the
+ various ticmarks (see `set xtics`).
+
+ Z grid lines are drawn on the bottom of the plot. This looks better if a
+ partial box is drawn around the plot---see `set border`.
+3 hidden3d
+?commands set hidden3d
+?commands unset hidden3d
+?commands show hidden3d
+?set hidden3d
+?unset hidden3d
+?show hidden3d
+?hidden3d
+?nohidden3d
+ The `set hidden3d` command enables hidden line removal for surface plotting
+ (see `splot`). Some optional features of the underlying algorithm can also
+ be controlled using this command.
+
+ Syntax:
+ set hidden3d {defaults} |
+ { {{offset <offset>} | {nooffset}}
+ {trianglepattern <bitpattern>}
+ {{undefined <level>} | {noundefined}}
+ {{no}altdiagonal}
+ {{no}bentover} }
+ unset hidden3d
+ show hidden3d
+
+ In contrast to the usual display in gnuplot, hidden line removal actually
+ treats the given function or data grids as real surfaces that can't be seen
+ through, so parts behind the surface will be hidden by it. For this to be
+ possible, the surface needs to have 'grid structure' (see `splot datafile`
+ about this), and it has to be drawn `with lines` or `with linespoints`.
+
+ When `hidden3d` is set, both the hidden portion of the surface and possibly
+ its contours drawn on the base (see `set contour`) as well as the grid will
+ be hidden. Each surface has its hidden parts removed with respect to itself
+ and to other surfaces, if more than one surface is plotted. Contours drawn
+ on the surface (`set contour surface`) don't work.
+
+ Labels and arrows are always visible and are unaffected. The key box is
+ never hidden by the surface. As of gnuplot version 4.2, `set hidden3d` also
+ affects 3D plotting styles `with points`, `with labels`, and `with vectors`,
+ even if no surface is present in the graph. Individual plots within the
+ graph may be explicitly excluded from this processing by appending the extra
+ option `nohidden3d` to the `with` specifier.
+
+ Hidden3d does not affect solid surfaces drawn using the pm3d mode. To
+ achieve a similar effect for pm3d surfaces, use instead set `pm3d depthorder`.
+
+ Functions are evaluated at isoline intersections. The algorithm interpolates
+ linearly between function points or data points when determining the visible
+ line segments. This means that the appearance of a function may be different
+ when plotted with `hidden3d` than when plotted with `nohidden3d` because in
+ the latter case functions are evaluated at each sample. Please see
+ `set samples` and `set isosamples` for discussion of the difference.
+
+ The algorithm used to remove the hidden parts of the surfaces has some
+ additional features controllable by this command. Specifying `defaults` will
+ set them all to their default settings, as detailed below. If `defaults` is
+ not given, only explicitly specified options will be influenced: all others
+ will keep their previous values, so you can turn on/off hidden line removal
+ via `set {no}hidden3d`, without modifying the set of options you chose.
+
+ The first option, `offset`, influences the linestyle used for lines on the
+ 'back' side. Normally, they are drawn in a linestyle one index number higher
+ than the one used for the front, to make the two sides of the surface
+ distinguishable. You can specify a different line style offset to add
+ instead of the default 1, by `offset <offset>`. Option `nooffset` stands for
+ `offset 0`, making the two sides of the surface use the same linestyle.
+
+ Next comes the option `trianglepattern <bitpattern>`. <bitpattern> must be
+ a number between 0 and 7, interpreted as a bit pattern. Each bit determines
+ the visibility of one edge of the triangles each surface is split up into.
+ Bit 0 is for the 'horizontal' edges of the grid, Bit 1 for the 'vertical'
+ ones, and Bit 2 for the diagonals that split each cell of the original grid
+ into two triangles. The default pattern is 3, making all horizontal and
+ vertical lines visible, but not the diagonals. You may want to choose 7 to
+ see those diagonals as well.
+
+ The `undefined <level>` option lets you decide what the algorithm is to do
+ with data points that are undefined (missing data, or undefined function
+ values), or exceed the given x-, y- or z-ranges. Such points can either be
+ plotted nevertheless, or taken out of the input data set. All surface
+ elements touching a point that is taken out will be taken out as well, thus
+ creating a hole in the surface. If <level> = 3, equivalent to option
+ `noundefined`, no points will be thrown away at all. This may produce all
+ kinds of problems elsewhere, so you should avoid this. <level> = 2 will
+ throw away undefined points, but keep the out-of-range ones. <level> = 1,
+ the default, will get rid of out-of-range points as well.
+
+ By specifying `noaltdiagonal`, you can override the default handling of a
+ special case can occur if `undefined` is active (i.e. <level> is not 3).
+ Each cell of the grid-structured input surface will be divided in two
+ triangles along one of its diagonals. Normally, all these diagonals have
+ the same orientation relative to the grid. If exactly one of the four cell
+ corners is excluded by the `undefined` handler, and this is on the usual
+ diagonal, both triangles will be excluded. However if the default setting
+ of `altdiagonal` is active, the other diagonal will be chosen for this cell
+ instead, minimizing the size of the hole in the surface.
+
+ The `bentover` option controls what happens to another special case, this
+ time in conjunction with the `trianglepattern`. For rather crumply surfaces,
+ it can happen that the two triangles a surface cell is divided into are seen
+ from opposite sides (i.e. the original quadrangle is 'bent over'), as
+ illustrated in the following ASCII art:
+
+ C----B
+ original quadrangle: A--B displayed quadrangle: |\ |
+ ("set view 0,0") | /| ("set view 75,75" perhaps) | \ |
+ |/ | | \ |
+ C--D | \|
+ A D
+
+ If the diagonal edges of the surface cells aren't generally made visible by
+ bit 2 of the <bitpattern> there, the edge CB above wouldn't be drawn at all,
+ normally, making the resulting display hard to understand. Therefore, the
+ default option of `bentover` will turn it visible in this case. If you don't
+ want that, you may choose `nobentover` instead.
+ See also
+^ <a href="http://www.gnuplot.info/demo/hidden.html">
+ hidden line removal demo (hidden.dem)
+^ </a>
+ and
+^ <a href="http://www.gnuplot.info/demo/singulr.html">
+ complex hidden line demo (singulr.dem).
+^ </a>
+3 historysize
+?commands set historysize
+?set historysize
+?unset historysize
+?historysize
+?nohistorysize
+ Note: the command `set historysize` is only available when
+ gnuplot has been configured with the GNU readline.
+
+ Syntax:
+ set historysize <int>
+ unset historysize
+
+ When leaving gnuplot, the value of historysize is used for
+ truncating the history to at most that much lines. The default
+ is 500.
+ `unset historysize` will disable history truncation and thus
+ allow an infinite number of lines to be written to the history
+ file.
+3 isosamples
+?commands set isosamples
+?commands show isosamples
+?set isosamples
+?show isosamples
+?isosamples
+ The isoline density (grid) for plotting functions as surfaces may be changed
+ by the `set isosamples` command.
+
+ Syntax:
+ set isosamples <iso_1> {,<iso_2>}
+ show isosamples
+
+ Each function surface plot will have <iso_1> iso-u lines and <iso_2> iso-v
+ lines. If you only specify <iso_1>, <iso_2> will be set to the same value
+ as <iso_1>. By default, sampling is set to 10 isolines per u or v axis.
+ A higher sampling rate will produce more accurate plots, but will take longer.
+ These parameters have no effect on data file plotting.
+
+ An isoline is a curve parameterized by one of the surface parameters while
+ the other surface parameter is fixed. Isolines provide a simple means to
+ display a surface. By fixing the u parameter of surface s(u,v), the iso-u
+ lines of the form c(v) = s(u0,v) are produced, and by fixing the v parameter,
+ the iso-v lines of the form c(u) = s(u,v0) are produced.
+
+ When a function surface plot is being done without the removal of hidden
+ lines, `set samples` controls the number of points sampled along each
+ isoline; see `set samples` and `set hidden3d`. The contour algorithm
+ assumes that a function sample occurs at each isoline intersection, so
+ change in `samples` as well as `isosamples` may be desired when changing
+ the resolution of a function surface/contour.
+3 key
+?commands set key
+?commands unset key
+?commands show key
+?set key
+?unset key
+?show key
+?key
+?nokey
+?legend
+ The `set key` command enables a key (or legend) describing plots on a plot.
+
+ The contents of the key, i.e., the names given to each plotted data set and
+ function and samples of the lines and/or symbols used to represent them, are
+ determined by the `title` and `with` options of the {`s`}`plot` command.
+ Please see `plot title` and `plot with` for more information.
+
+ Syntax:
+ set key {on|off} {default}
+ {{inside | outside} | {lmargin | rmargin | tmargin | bmargin}
+ | {at <position>}}
+ {left | right | center} {top | bottom | center}
+ {vertical | horizontal} {Left | Right}
+ {{no}reverse} {{no}invert}
+ {samplen <sample_length>} {spacing <vertical_spacing>}
+ {width <width_increment>}
+ {height <height_increment>}
+ {{no}autotitle {columnheader}}
+ {title "<text>"} {{no}enhanced}
+ {{no}box { {linestyle | ls <line_style>}
+ | {linetype | lt <line_type>}
+ {linewidth | lw <line_width>}}}
+ unset key
+ show key
+
+ Plots may be drawn with no visible key by requesting `set key off` or
+ `unset key`.
+
+ Elements within the key are stacked according to `vertical` or `horizontal`.
+ In the case of `vertical`, the key occupies as few columns as possible. That
+ is, elements are aligned in a column until running out of vertical space at
+ which point a new column is started. In the case of `horizontal`, the key
+ occupies as few rows as possible.
+
+ By default the key is placed in the upper right inside corner of the graph.
+ The keywords `left`, `right`, `top`, `bottom`, `center`, `inside`, `outside`,
+ `lmargin`, `rmargin`, `tmargin`, `bmargin` (, `above`, `over`, `below` and
+ `under`) may be used to automatically place the key in other positions of the
+ graph. Also an `at <position>` may be given to indicate precisely where the
+ plot should be placed. In this case, the keywords `left`, `right`, `top`,
+ `bottom` and `center` serve an analogous purpose for alignment.
+
+ To understand positioning, the best concept is to think of a region, i.e.,
+ inside/outside, or one of the margins. Along with the region, keywords
+ `left/center/right` (l/c/r) and `top/center/bottom` (t/c/b) control where
+ within the particular region the key should be placed.
+
+ When in `inside` mode, the keywords `left` (l), `right` (r), `top` (t),
+ `bottom` (b), and `center` (c) push the key out toward the plot boundary as
+ illustrated:
+
+ t/l t/c t/r
+
+ c/l c c/r
+
+ b/l b/c b/r
+
+
+ When in `outside` mode, automatic placement is similar to the above
+ illustration, but with respect to the view, rather than the graph boundary.
+ That is, a border is moved inward to make room for the key outside of
+ the plotting area, although this may interfere with other labels and may
+ cause an error on some devices. The particular plot border that is moved
+ depends upon the position described above and the stacking direction. For
+ options centered in one of the dimensions, there is no ambiguity about which
+ border to move. For the corners, when the stack direction is `vertical`, the
+ left or right border is moved inward appropriately. When the stack direction
+ is `horizontal`, the top or bottom border is moved inward appropriately.
+
+ The margin syntax allows automatic placement of key regardless of stack
+ direction. When one of the margins `lmargin` (lm), `rmargin` (rm),
+ `tmargin` (tm), and `bmargin` (bm) is combined with a single, non-conflicting
+ direction keyword, the following illustrated positions may contain the key:
+
+ l/tm c/tm r/tm
+
+ t/lm t/rm
+
+ c/lm c/rm
+
+ b/lm b/rm
+
+ l/bm c/bm r/bm
+
+
+ Keywords `above` and `over` are synonymous with `tmargin`. For version
+ compatibility, `above` or `over` without an additional l/c/r or stack direction
+ keyword uses `center` and `horizontal`. Keywords `below` and `under` are
+ synonymous with `bmargin`. For compatibility, `below` or `under` without an
+ additional l/c/r or stack direction keyword uses `center` and `horizontal`. A
+ further compatibility issue is that `outside` appearing without an additional
+ t/b/c or stack direction keyword uses `top`, `right` and `vertical` (i.e., the
+ same as t/rm above).
+
+ The <position> can be a simple x,y,z as in previous versions, but these can
+ be preceded by one of five keywords (`first`, `second`, `graph`, `screen`,
+ `character`) which selects the coordinate system in which the position of
+ the first sample line is specified. See `coordinates` for more details.
+ The effect of `left`, `right`, `top`, `bottom`, and `center` when <position>
+ is given is to align the key as though it were text positioned using the
+ label command, i.e., `left` means left align with key to the right of
+ <position>, etc.
+
+ Justification of the labels within the key is controlled by `Left` or `Right`
+ (default is `Right`). The text and sample can be reversed (`reverse`) and a
+ box can be drawn around the key (`box {...}`) in a specified `linetype`
+ and `linewidth`, or a user-defined `linestyle`. Note that not all
+ terminal drivers support linewidth selection, though.
+
+ By default the first plot label is at the top of the key and successive labels
+ are entered below it. The `invert` option causes the first label to be placed
+ at the bottom of the key, with successive labels entered above it. This option
+ is useful to force the vertical ordering of labels in the key to match the
+ order of box types in a stacked histogram.
+
+ The length of the sample line can be controlled by `samplen`. The sample
+ length is computed as the sum of the tic length and <sample_length> times the
+ character width. `samplen` also affects the positions of point samples in
+ the key since these are drawn at the midpoint of the sample line, even if
+ the sample line itself is not drawn.
+
+ The vertical spacing between lines is controlled by `spacing`. The spacing
+ is set equal to the product of the pointsize, the vertical tic size, and
+ <vertical_spacing>. The program will guarantee that the vertical spacing is
+ no smaller than the character height.
+
+ The <width_increment> is a number of character widths to be added to or
+ subtracted from the length of the string. This is useful only when you are
+ putting a box around the key and you are using control characters in the text.
+ `gnuplot` simply counts the number of characters in the string when computing
+ the box width; this allows you to correct it.
+
+ The <height_increment> is a number of character heights to be added to or
+ subtracted from the height of the key box. This is useful mainly when you are
+ putting a box around the key, otherwise it can be used to adjust the vertical
+ shift of automatically chosen key position by <height_increment>/2.
+
+ All plotted curves of `plot`s and `splot`s are titled according to the
+ default option `autotitles`. The automatic generation of titles can be
+ suppressed by `noautotitles`; then only those titles explicitly defined
+ by `(s)plot ... title ...` will be drawn.
+
+ The `set key autotitle columnheader` option is available if gnuplot was built
+ with --enable-datastrings. This command causes the first entry in each column
+ of plotted data to be interpreted as a text string and used as a title for
+ the corresponding plot. If the quantity being plotted is a function of data
+ from several columns, gnuplot may be confused as to which column to draw the
+ title from. In this case it is necessary to specify the column explicitly in
+ the plot command, e.g. `plot "datafile" using (($2+$3)/$4) title 3 with lines`.
+
+ A title can be put on the key (`title "<text>"`)---see also `syntax` for the
+ distinction between text in single- or double-quotes. The key title uses the
+ same justification as do the plot titles.
+
+ An explicitly given title is typeset using enhanced text properties on
+ terminals supporting this, see `enhanced text` for more details.
+ This default behavior can be switched off by the `noenhanced` option.
+
+ The defaults for `set key` are `on`, `right`, `top`, `vertical`, `Right`,
+ `noreverse`, `noinvert`, `samplen 4`, `spacing 1.25`, `title ""`, and
+ `nobox`. The default <linetype> is the same as that used for the plot
+ borders. Entering `set key default` returns the key to its default
+ configuration.
+
+ The key is drawn as a sequence of lines, with one plot described on each
+ line. On the right-hand side (or the left-hand side, if `reverse` is
+ selected) of each line is a representation that attempts to mimic the way the
+ curve is plotted. On the other side of each line is the text description
+ (the line title), obtained from the `plot` command. The lines are vertically
+ arranged so that an imaginary straight line divides the left- and right-hand
+ sides of the key. It is the coordinates of the top of this line that are
+ specified with the `set key` command. In a `plot`, only the x and y
+ coordinates are used to specify the line position. For a `splot`, x, y and
+ z are all used as a 3-d location mapped using the same mapping as the graph
+ itself to form the required 2-d screen position of the imaginary line.
+
+ When using the TeX or PostScript drivers, or similar drivers where formatting
+ information is embedded in the string, `gnuplot` is unable to calculate
+ correctly the width of the string for key positioning. If the key is to be
+ positioned at the left, it may be convenient to use the combination `set key
+ left Left reverse`. The box and gap in the grid will be the width of the
+ literal string.
+
+ If `splot` is being used to draw contours, the contour labels will be listed
+ in the key. If the alignment of these labels is poor or a different number
+ of decimal places is desired, the label format can be specified. See
+ `set clabel` for details.
+
+ Examples:
+
+ This places the key at the default location:
+ set key default
+
+ This disables the key:
+ unset key
+
+ This places a key at coordinates 2,3.5,2 in the default (first) coordinate
+ system:
+ set key at 2,3.5,2
+
+ This places the key below the graph:
+ set key below
+
+ This places the key in the bottom left corner, left-justifies the text,
+ gives it a title, and draws a box around it in linetype 3:
+ set key left bottom Left title 'Legend' box 3
+3 label
+?commands set label
+?commands unset label
+?commands show label
+?set label
+?unset label
+?show label
+?label
+?nolabel
+ Arbitrary labels can be placed on the plot using the `set label` command.
+
+ Syntax:
+ set label {<tag>} {"<label text>"} {at <position>}
+ {left | center | right}
+ {norotate | rotate {by <degrees>}}
+ {font "<name>{,<size>}"}
+ {noenhanced}
+ {front | back}
+ {textcolor <colorspec>}
+ {point <pointstyle> | nopoint}
+ {offset <offset>}
+ unset label {<tag>}
+ show label
+
+ The <position> is specified by either x,y or x,y,z, and may be preceded by
+ `first`, `second`, `graph`, `screen`, or `character` to select the coordinate
+ system. See `coordinates` for details.
+
+ The tag is an integer that is used to identify the label. If no <tag>
+ is given, the lowest unused tag value is assigned automatically. The
+ tag can be used to delete or modify a specific label. To change any
+ attribute of an existing label, use the `set label` command with the
+ appropriate tag, and specify the parts of the label to be changed.
+
+ The <label text> can be a string constant, a string variable, or a string-
+ valued expression. See `strings`, `sprintf`, and `gprintf`.
+
+ By default, the text is placed flush left against the point x,y,z. To adjust
+ the way the label is positioned with respect to the point x,y,z, add the
+ justification parameter, which may be `left`, `right` or `center`,
+ indicating that the point is to be at the left, right or center of the text.
+ Labels outside the plotted boundaries are permitted but may interfere with
+ axis labels or other text.
+
+ If `rotate` is given, the label is written vertically (if the terminal can do
+ so, of course). If `rotate by <degrees>` is given, conforming terminals will
+ try to write the text at the specified angle; non-conforming terminals will
+ treat this as vertical text.
+
+ Font and its size can be chosen explicitly by `font "<name>{,<size>}"` if the
+ terminal supports font settings. Otherwise the default font of the terminal
+ will be used.
+
+ Normally the enhanced text mode string interpretation, if enabled for the
+ current terminal, is applied to all text strings including label text.
+ The `noenhanced` property can be used to exempt a specific label from the
+ enhanced text mode processing. The can be useful if the label contains
+ underscores, for example. See `enhanced text`.
+
+ If `front` is given, the label is written on top of the graphed data. If
+ `back` is given (the default), the label is written underneath the graphed
+ data. Using `front` will prevent a label from being obscured by dense data.
+
+ `textcolor <colorspec>` changes the color of the label text. <colorspec> can be
+ a linetype, an rgb color, or a palette mapping. See help for `colorspec` and
+ `palette`. `textcolor` may be abbreviated `tc`.
+ `tc default` resets the text color to its default state.
+ `tc lt <n>` sets the text color to that of line type <n>.
+ `tc ls <n>` sets the text color to that of line style <n>.
+ `tc palette z` selects a palette color corresponding to the label z position.
+ `tc palette cb <val>` selects a color corresponding to <val> on the colorbar.
+ `tc palette fraction <val>`, with 0<=val<=1, selects a color corresponding to
+ the mapping [0:1] to grays/colors of the `palette`.
+ `tc rgb "#RRGGBB"` selects an arbitrary 24-bit RGB color.
+
+ If a <pointstyle> is given, using keywords `lt`, `pt` and `ps`, see `style`,
+ a point with the given style and color of the given line type is plotted at
+ the label position and the text of the label is displaced slightly.
+ This option is used by default for placing labels in `mouse` enhanced
+ terminals. Use `nopoint` to turn off the drawing of a point near
+ the label (this is the default).
+
+ The displacement defaults to 1,1 in `pointsize` units if a <pointstyle> is
+ given, 0,0 if no <pointstyle> is given. The displacement can be controlled
+ by the optional `offset <offset>` where <offset> is specified by either x,y
+ or x,y,z, and may be preceded by `first`, `second`, `graph`, `screen`, or
+ `character` to select the coordinate system. See `coordinates` for details.
+
+ If one (or more) axis is timeseries, the appropriate coordinate should be
+ given as a quoted time string according to the `timefmt` format string.
+ See `set xdata` and `set timefmt`.
+
+ The EEPIC, Imagen, LaTeX, and TPIC drivers allow \\ in a string to specify
+ a newline.
+
+ Examples:
+
+ To set a label at (1,2) to "y=x", use:
+ set label "y=x" at 1,2
+
+ To set a Sigma of size 24, from the Symbol font set, at the center of
+ the graph, use:
+ set label "S" at graph 0.5,0.5 center font "Symbol,24"
+
+ To set a label "y=x^2" with the right of the text at (2,3,4), and tag the
+ label as number 3, use:
+ set label 3 "y=x^2" at 2,3,4 right
+
+ To change the preceding label to center justification, use:
+ set label 3 center
+
+ To delete label number 2, use:
+ unset label 2
+
+ To delete all labels, use:
+ unset label
+
+ To show all labels (in tag order), use:
+ show label
+
+ To set a label on a graph with a timeseries on the x axis, use, for example:
+ set timefmt "%d/%m/%y,%H:%M"
+ set label "Harvest" at "25/8/93",1
+
+ To display a freshly fitted parameter on the plot with the data and the
+ fitted function, do this after the `fit`, but before the `plot`:
+ set label sprintf("a = %3.5g",par_a) at 30,15
+ bfit = gprintf("b = %s*10^%S",par_b)
+ set label bfit at 30,20
+
+ To set a label displaced a little bit from a small point:
+ set label 'origin' at 0,0 point lt 1 pt 2 ps 3 offset 1,-1
+
+ To set a label whose color matches the z value (in this case 5.5) of some
+ point on a 3D splot colored using pm3d:
+ set label 'text' at 0,0,5.5 tc palette z
+
+3 lmargin
+?commands set lmargin
+?set lmargin
+?lmargin
+ The command `set lmargin` sets the size of the left margin.
+ Please see `set margin` for details.
+3 loadpath
+?commands set loadpath
+?commands show loadpath
+?set loadpath
+?show loadpath
+?loadpath
+ The `loadpath` setting defines additional locations for data and command
+ files searched by the `call`, `load`, `plot` and `splot` commands. If a
+ file cannot be found in the current directory, the directories in
+ `loadpath` are tried.
+
+ Syntax:
+ set loadpath {"pathlist1" {"pathlist2"...}}
+ show loadpath
+
+ Path names may be entered as single directory names, or as a list of
+ path names separated by a platform-specific path separator, eg. colon
+ (':') on Unix, semicolon (';') on DOS/Windows/OS/2/Amiga platforms.
+ The `show loadpath`, `save` and `save set` commands replace the
+ platform-specific separator with a space character (' ') for maximum
+ portability.
+
+ If the environment variable GNUPLOT_LIB is set, its contents are
+ appended to `loadpath`. However, `show loadpath` prints the contents
+ of user defined loadpath and system loadpath separately. Also, the
+ `save` and `save set` commands save only the user specified parts of
+ `loadpath`, for portability reasons.
+3 locale
+?commands set locale
+?set locale
+?locale
+ The `locale` setting determines the language with which `{x,y,z}{d,m}tics`
+ will write the days and months.
+
+ Syntax:
+ set locale {"<locale>"}
+
+ <locale> may be any language designation acceptable to your installation.
+ See your system documentation for the available options. The default value
+ is determined from the LC_TIME, LC_ALL, or LANG environment variables.
+
+ To change the decimal point locale, see `set decimalsign`.
+3 logscale
+?commands set logscale
+?commands unset logscale
+?commands show logscale
+?set logscale
+?unset logscale
+?show logscale
+?set log
+?logscale
+?nologscale
+ Syntax:
+ set logscale <axes> <base>
+ unset logscale <axes>
+ show logscale
+
+ where <axes> may be any combination of `x`, `x2`, `y`, `y2`, `z`, and `cb` in
+ any order, and where <base> is the base of the log scaling. If <base> is not
+ given, then 10 is assumed. If <axes> is not given, then all axes are assumed.
+ `unset logscale` turns off log scaling for the specified axes.
+
+ Examples:
+
+ To enable log scaling in both x and z axes:
+ set logscale xz
+
+ To enable scaling log base 2 of the y axis:
+ set logscale y 2
+
+ To enable z and color log axes for a pm3d plot:
+ set logscale zcb
+
+ To disable z axis log scaling:
+ unset logscale z
+3 macros
+?commands set macros
+?commands show macros
+?set macros
+?show macros
+ If command line macro substitution is enabled, then tokens in the command line
+ of the form @<stringvariablename> will be replaced by the text string contained
+ in <stringvariablename>. See `substitution`.
+
+ Syntax:
+ set macros
+
+3 mapping
+?commands set mapping
+?commands show mapping
+?set mapping
+?show mapping
+?mapping
+ If data are provided to `splot` in spherical or cylindrical coordinates,
+ the `set mapping` command should be used to instruct `gnuplot` how to
+ interpret them.
+
+ Syntax:
+ set mapping {cartesian | spherical | cylindrical}
+
+ A cartesian coordinate system is used by default.
+
+ For a spherical coordinate system, the data occupy two or three columns
+ (or `using` entries). The first two are interpreted as the azimuthal
+ and polar angles theta and phi (or "longitude" and "latitude"), in the
+ units specified by `set angles`. The radius r is taken from the third
+ column if there is one, or is set to unity if there is no third column.
+ The mapping is:
+
+ x = r * cos(theta) * cos(phi)
+ y = r * sin(theta) * cos(phi)
+ z = r * sin(phi)
+
+ Note that this is a "geographic" spherical system, rather than a "polar"
+ one (that is, phi is measured from the equator, rather than the pole).
+
+ For a cylindrical coordinate system, the data again occupy two or three
+ columns. The first two are interpreted as theta (in the units specified by
+ `set angles`) and z. The radius is either taken from the third column or set
+ to unity, as in the spherical case. The mapping is:
+
+ x = r * cos(theta)
+ y = r * sin(theta)
+ z = z
+
+ The effects of `mapping` can be duplicated with the `using` filter on the
+ `splot` command, but `mapping` may be more convenient if many data files are
+ to be processed. However even if `mapping` is used, `using` may still be
+ necessary if the data in the file are not in the required order.
+
+ `mapping` has no effect on `plot`.
+^ See also
+^ <a href="http://www.gnuplot.info/demo/world.html">
+ world.dem: mapping demos.
+^ </a>
+3 margin
+?commands set margin
+?commands show margin
+?set margin
+?show margin
+?margin
+ The computed margins can be overridden by the `set margin` commands. `show
+ margin` shows the current settings.
+
+ Syntax:
+ set bmargin {{at screen} <margin>}
+ set lmargin {{at screen} <margin>}
+ set rmargin {{at screen} <margin>}
+ set tmargin {{at screen} <margin>}
+ show margin
+
+ The default units of <margin> are character heights or widths, as appropriate.
+ A positive value defines the absolute size of the margin. A negative value
+ (or none) causes `gnuplot` to revert to the computed value. For 3D plots,
+ only the left margin can be set using character units.
+
+ The keywords `at screen` indicates that the margin is specified as a fraction
+ of the full drawing area. This can be used to precisely line up the corners of
+ individual 2D and 3D graphs in a multiplot. This placement ignores the current
+ values of `set origin` and `set size`, and is intended as an alternative
+ method for positioning graphs within a multiplot.
+
+ Normally the margins of a plot are automatically calculated based on tics,
+ tic labels, axis labels, the plot title, the timestamp and the size of the
+ key if it is outside the borders. If, however, tics are attached to the
+ axes (`set xtics axis`, for example), neither the tics themselves nor their
+ labels will be included in either the margin calculation or the calculation
+ of the positions of other text to be written in the margin. This can lead
+ to tic labels overwriting other text if the axis is very close to the border.
+3 mouse
+?commands set mouse
+?commands unset mouse
+?set mouse
+?unset mouse
+?mouse
+?nomouse
+ The command `set mouse` enables mouse actions. Currently the pm, x11, ggi,
+ windows and wxt terminals are mouse enhanced. There are two mouse modes. The
+ 2d-graph mode works for 2d graphs and for maps (i.e. splots with `set view`
+ having z-rotation 0, 90, 180, 270 or 360 degrees, including `set view map`)
+ and it allows tracing the position over graph, zooming, annotating graph etc.
+ For 3d graphs `splot`, the view and scaling of the graph can be changed with
+ mouse buttons 1 and 2. If additionally to these buttons the modifier <ctrl> is
+ hold down, the coordinate system only is rotated which is useful for large
+ data sets. A vertical motion of Button 2 with the shift key hold down changes
+ the `ticslevel`.
+
+ Mousing is not available in multiplot mode. When multiplot is finished using
+ `unset multiplot`, then the mouse will be turned on again and acts on the
+ last plot (like replot does).
+
+ Syntax:
+ set mouse {doubleclick <ms>} {nodoubleclick} \
+ {{no}zoomcoordinates} \
+ {noruler | ruler {at x,y}} \
+ {polardistance{deg|tan} | nopolardistance} \
+ {format <string>} \
+ {clipboardformat <int>/<string>} \
+ {mouseformat <int>/<string>} \
+ {{no}labels} {labeloptions <string>} \
+ {{no}zoomjump} {{no}verbose}
+ unset mouse
+
+ The doubleclick resolution is given in milliseconds and used for Button 1
+ which copies the current mouse position to the `clipboard`. If you want that
+ to be done by single clicking a value of 0 ms can be used. The default value
+ is 300 ms.
+
+ The option `zoomcoordinates` determines if the coordinates of the zoom box are
+ drawn at the edges while zooming. This is on by default.
+
+ The options `noruler` and `ruler` switch the ruler off and on, the latter
+ optionally at given `coordinates`. This corresponds to the default key binding
+ 'r'.
+
+ The option `polardistance` determines if the distance between the mouse cursor
+ and the ruler is also shown in polar coordinates (distance and angle in
+ degrees or tangent (slope)). This corresponds to the default key binding '5'.
+
+ The `format` option takes a fprintf like format string which determines how
+ floating point numbers are printed to the drivers window and the clipboard.
+ The default is "% #g".
+
+ `clipboardformat` and `mouseformat` are used for formatting the text on
+ Button1 and Button2 actions -- copying the coordinates to the clipboard and
+ temporarily annotating the mouse position. This corresponds to the key
+ bindings '1', '2', '3', '4' (see the drivers's help window). If the argument
+ is a string this string is used as c format specifier and should contain two
+ float specifiers, e.g. `set mouse mouseformat "mouse = %5.2g, %10.2f"`. Use
+ `set mouse mouseformat ""` to turn this string off again.
+
+ The following formats are available (format 6 may only be selected if the
+ format string was specified already):
+
+ 0 real coordinates in brackets e.g. [1.23, 2.45]
+ 1 real coordinates w/o brackets e.g. 1.23, 2.45
+ 2 x == timefmt [(as set by `set timefmt`), 2.45]
+ 3 x == date [31. 12. 1999, 2.45]
+ 4 x == time [23:59, 2.45]
+ 5 x == date / time [31. 12. 1999 23:59, 2.45]
+ 6 alt. format, specified as string ""
+
+ Choose the option `labels` to get real gnuplot labels on Button 2. (The
+ default is `nolabels` which makes Button 2 drawing only temporary annotations
+ at the mouse positions). The labels are drawn with the current setting of
+ `mouseformat`. `labeloptions` controls which options are passed to the
+ `set label` command. The default is "pointstyle 1" which will plot a small
+ plus at the label position. Note that the pointsize is taken from the
+ `set pointsize` command.
+ Labels can be removed by holding the Ctrl-Key down while clicking with
+ Button 2 on the label's point. The threshold for how close you must be to the
+ label is also determined by the `pointsize`.
+
+ If the option `zoomjump` is on, the mouse pointer will be automatically
+ offset a small distance after starting a zoom region with button 3. This can
+ be useful to avoid a tiny (or even empty) zoom region. `zoomjump` is off by
+ default.
+
+ If the option `verbose` is turned on the communication commands are shown
+ during execution. This option can also be toggled by hitting `6` in the
+ driver's window. `verbose` is off by default.
+
+ Press 'h' in the driver's window for a short summary of the mouse and key
+ bindings. This will also display user defined bindings or `hotkeys` which
+ can be defined using the `bind` command, see help for `bind`. Note, that user
+ defined `hotkeys` may override the default bindings.
+
+ Press 'q' in the driver's window to close the window. This key cannot be
+ overridden with the `bind` command.
+
+ See also help for `bind` and `label`.
+4 X11 mouse
+?mouse x11_mouse
+?x11_mouse
+?x11 mouse
+ If multiple X11 plot windows have been opened using the `set term x11 <n>`
+ terminal option, then only the current plot window supports the entire
+ range of mouse commands and hotkeys. The other windows will, however,
+ continue to display mouse coordinates at the lower left.
+
+ For consistency with other screen terminals, X11 mouse support is turned on by
+ default, wherever the standard input comes from. However, on some UNIX
+ flavors, special input devices as /dev/null might not be `select-able`; using
+ such devices with the mouse turned on will hang gnuplot. Please turn off
+ mousing with `unset mouse` if you are in this situation.
+3 multiplot
+?commands set multiplot
+?commands unset multiplot
+?set multiplot
+?unset multiplot
+?multiplot
+?nomultiplot
+ The command `set multiplot` places `gnuplot` in the multiplot mode, in which
+ several plots are placed on the same page, window, or screen.
+
+ Syntax:
+ set multiplot { layout <rows>,<cols>
+ {rowsfirst|columnsfirst} {downwards|upwards}
+ {title <page title>}
+ {scale <xscale>{,<yscale>}} {offset <xoff>{,<yoff>}}
+ }
+ unset multiplot
+
+ For some terminals, no plot is displayed until the command `unset multiplot`
+ is given, which causes the entire page to be drawn and then returns gnuplot
+ to its normal single-plot mode. For other terminals, each separate `plot`
+ command produces an updated display, either by redrawing all previous ones
+ and the newly added plot, or by just adding the new plot to the existing
+ display.
+
+ The area to be used by the next plot is not erased before doing the
+ new plot. The `clear` command can be used to do this if wanted, as is
+ typically the case for "inset" plots.
+
+ Any labels or arrows that have been defined will be drawn for each plot
+ according to the current size and origin (unless their coordinates are
+ defined in the `screen` system). Just about everything else that can be
+ `set` is applied to each plot, too. If you want something to appear only
+ once on the page, for instance a single time stamp, you'll need to put a `set
+ time`/`unset time` pair around one of the `plot`, `splot` or `replot`
+ commands within the `set multiplot`/`unset multiplot` block.
+
+ The multiplot title is separate from the individual plot titles, if any.
+ Space is reserved for it at the top of the page, spanning the full width
+ of the canvas.
+
+ The commands `set origin` and `set size` must be used to correctly position
+ each plot if no layout is specified or if fine tuning is desired. See
+ `set origin` and `set size` for details of their usage.
+
+ Example:
+ set multiplot
+ set size 0.4,0.4
+ set origin 0.1,0.1
+ plot sin(x)
+ set size 0.2,0.2
+ set origin 0.5,0.5
+ plot cos(x)
+ unset multiplot
+
+ This displays a plot of cos(x) stacked above a plot of sin(x).
+
+ `set size` and `set origin` refer to the entire plotting area used for each
+ plot. Please also see `set term size`. If you want to have the axes
+ themselves line up, you can guarantee that the margins are the same size with
+ the `set margin` commands. See `set margin` for their use. Note that the
+ margin settings are absolute, in character units, so the appearance of the
+ graph in the remaining space will depend on the screen size of the display
+ device, e.g., perhaps quite different on a video display and a printer.
+
+ With the `layout` option you can generate simple multiplots without having
+ to give the `set size` and `set origin` commands before each plot: Those
+ are generated automatically, but can be overridden at any time. With
+ `layout` the display will be divided by a grid with <rows> rows and
+ <cols> columns. This grid is filled rows first or columns first depending on
+ whether the corresponding option is given in the multiplot command. The stack
+ of plots can grow `downwards` or `upwards`.
+ Default is `rowsfirst` and `downwards`.
+
+ Each plot can be scaled by `scale` and shifted with `offset`; if the y-values
+ for scale or offset are omitted, the x-value will be used. `unset multiplot`
+ will turn off the automatic layout and restore the values of `set size` and
+ `set origin` as they were before `set multiplot layout`.
+
+ Example:
+ set size 1,1
+ set origin 0,0
+ set multiplot layout 3,2 columnsfirst scale 1.1,0.9
+ [ up to 6 plot commands here ]
+ unset multiplot
+
+ The above example will produce 6 plots in 2 columns filled top to bottom,
+ left to right. Each plot will have a horizontal size of 1.1/2 and a vertical
+ size of 0.9/3.
+
+ See also
+^ <a href="http://gnuplot.sourceforge.net/demo/multiplt.html">
+ multiplot demo (multiplt.dem)
+^ </a>
+3 mx2tics
+?commands set mx2tics
+?commands unset mx2tics
+?commands show mx2tics
+?set mx2tics
+?unset mx2tics
+?show mx2tics
+?mx2tics
+?nomx2tics
+ Minor tic marks along the x2 (top) axis are controlled by `set mx2tics`.
+ Please see `set mxtics`.
+3 mxtics
+?commands set mxtics
+?commands unset mxtics
+?commands show mxtics
+?set mxtics
+?unset mxtics
+?show mxtics
+?mxtics
+?nomxtics
+ Minor tic marks along the x axis are controlled by `set mxtics`. They can be
+ turned off with `unset mxtics`. Similar commands control minor tics along
+ the other axes.
+
+ Syntax:
+ set mxtics {<freq> | default}
+ unset mxtics
+ show mxtics
+
+ The same syntax applies to `mytics`, `mztics`, `mx2tics`, `my2tics` and
+ `mcbtics`.
+
+ <freq> is the number of sub-intervals (NOT the number of minor tics) between
+ major tics (the default for a linear axis is either two or five
+ depending on the major tics, so there are one or four minor
+ tics between major tics). Selecting `default` will return the number of minor
+ ticks to its default value.
+
+ If the axis is logarithmic, the number of sub-intervals will be set to a
+ reasonable number by default (based upon the length of a decade). This will
+ be overridden if <freq> is given. However the usual minor tics (2, 3, ...,
+ 8, 9 between 1 and 10, for example) are obtained by setting <freq> to 10,
+ even though there are but nine sub-intervals.
+
+ To set minor tics at arbitrary positions, use the ("<label>" <pos> <level>,
+ ...) form of `set {x|x2|y|y2|z}tics` with <label> empty and <level> set to 1.
+
+ The `set m{x|x2|y|y2|z}tics` commands work only when there are uniformly
+ spaced major tics. If all major tics were placed explicitly by
+ `set {x|x2|y|y2|z}tics`, then minor tic commands are ignored. Implicit
+ major tics and explicit minor tics can be combined using
+ `set {x|x2|y|y2|z}tics` and `set {x|x2|y|y2|z}tics add`.
+
+ Examples:
+ set xtics 0, 5, 10
+ set xtics add (7.5)
+ set mxtics 5
+ Major tics at 0,5,7.5,10, minor tics at 1,2,3,4,6,7,8,9
+ set logscale y
+ set ytics format ""
+ set ytics 1e-6, 10, 1
+ set ytics add ("1" 1, ".1" 0.1, ".01" 0.01, "10^-3" 0.001, \
+ "10^-4" 0.0001)
+ set mytics 10
+ Major tics with special formatting, minor tics at log positions
+
+ By default, minor tics are off for linear axes and on for logarithmic axes.
+ They inherit the settings for `axis|border` and `{no}mirror` specified for
+ the major tics. Please see `set xtics` for information about these.
+3 my2tics
+?commands set my2tics
+?commands unset my2tics
+?commands show my2tics
+?set my2tics
+?unset my2tics
+?show my2tics
+?my2tics
+?nomy2tics
+ Minor tic marks along the y2 (right-hand) axis are controlled by `set
+ my2tics`. Please see `set mxtics`.
+3 mytics
+?commands set mytics
+?commands unset mytics
+?commands show mytics
+?set mytics
+?unset mytics
+?show mytics
+?mytics
+?nomytics
+ Minor tic marks along the y axis are controlled by `set mytics`. Please
+ see `set mxtics`.
+3 mztics
+?commands set mztics
+?commands unset mztics
+?commands show mztics
+?set mztics
+?unset mztics
+?show mztics
+?mztics
+?nomztics
+ Minor tic marks along the z axis are controlled by `set mztics`. Please
+ see `set mxtics`.
+3 offsets
+?commands set offsets
+?commands unset offsets
+?commands show offsets
+?set offsets
+?unset offsets
+?show offsets
+?offsets
+?nooffsets
+ Offsets provide a mechanism to put a boundary around the data inside of an
+ autoscaled graph.
+
+ Syntax:
+ set offsets <left>, <right>, <top>, <bottom>
+ unset offsets
+ show offsets
+
+ Each offset may be a constant or an expression. Each defaults to 0. Left
+ and right offsets are given in units of the x axis, top and bottom offsets in
+ units of the y axis. A positive offset expands the graph in the specified
+ direction, e.g., a positive bottom offset makes ymin more negative. Negative
+ offsets, while permitted, can have unexpected interactions with autoscaling
+ and clipping.
+
+ Offsets are ignored in `splot`s.
+
+ Example:
+ set offsets 0, 0, 2, 2
+ plot sin(x)
+
+ This graph of sin(x) will have a y range [-3:3] because the function
+ will be autoscaled to [-1:1] and the vertical offsets are each two.
+3 origin
+?commands set origin
+?commands show origin
+?set origin
+?show origin
+?origin
+ The `set origin` command is used to specify the origin of a plotting surface
+ (i.e., the graph and its margins) on the screen. The coordinates are given
+ in the `screen` coordinate system (see `coordinates` for information about
+ this system).
+
+ Syntax:
+ set origin <x-origin>,<y-origin>
+3 output
+?commands set output
+?commands show output
+?set output
+?show output
+?output
+?output file
+ By default, screens are displayed to the standard output. The `set output`
+ command redirects the display to the specified file or device.
+
+ Syntax:
+ set output {"<filename>"}
+ show output
+
+ The filename must be enclosed in quotes. If the filename is omitted, any
+ output file opened by a previous invocation of `set output` will be closed
+ and new output will be sent to STDOUT. (If you give the command `set output
+ "STDOUT"`, your output may be sent to a file named "STDOUT"! ["May be", not
+ "will be", because some terminals, like `x11` or `wxt`, ignore `set output`.])
+
+ MSDOS users should note that the \ character has special significance in
+ double-quoted strings, so single-quotes should be used for filenames in
+ different directories.
+
+ When both `set terminal` and `set output` are used together, it is safest to
+ give `set terminal` first, because some terminals set a flag which is needed
+ in some operating systems. This would be the case, for example, if the
+ operating system needs to know whether or not a file is to be formatted in
+ order to open it properly.
+
+ On machines with popen functions (Unix), output can be piped through a shell
+ command if the first non-whitespace character of the filename is '|'.
+ For instance,
+
+ set output "|lpr -Plaser filename"
+ set output "|lp -dlaser filename"
+
+ On MSDOS machines, `set output "PRN"` will direct the output to the default
+ printer. On VMS, output can be sent directly to any spooled device. It is
+ also possible to send the output to DECnet transparent tasks, which allows
+ some flexibility.
+3 parametric
+?commands set parametric
+?commands unset parametric
+?commands show parametric
+?set parametric
+?unset parametric
+?show parametric
+?parametric
+?noparametric
+ The `set parametric` command changes the meaning of `plot` (`splot`) from
+ normal functions to parametric functions. The command `unset parametric`
+ restores the plotting style to normal, single-valued expression plotting.
+
+ Syntax:
+ set parametric
+ unset parametric
+ show parametric
+
+ For 2-d plotting, a parametric function is determined by a pair of parametric
+ functions operating on a parameter. An example of a 2-d parametric function
+ would be `plot sin(t),cos(t)`, which draws a circle (if the aspect ratio is
+ set correctly---see `set size`). `gnuplot` will display an error message if
+ both functions are not provided for a parametric `plot`.
+
+ For 3-d plotting, the surface is described as x=f(u,v), y=g(u,v), z=h(u,v).
+ Therefore a triplet of functions is required. An example of a 3-d parametric
+ function would be `cos(u)*cos(v),cos(u)*sin(v),sin(u)`, which draws a sphere.
+ `gnuplot` will display an error message if all three functions are not
+ provided for a parametric `splot`.
+
+ The total set of possible plots is a superset of the simple f(x) style plots,
+ since the two functions can describe the x and y values to be computed
+ separately. In fact, plots of the type t,f(t) are equivalent to those
+ produced with f(x) because the x values are computed using the identity
+ function. Similarly, 3-d plots of the type u,v,f(u,v) are equivalent to
+ f(x,y).
+
+ Note that the order the parametric functions are specified is xfunction,
+ yfunction (and zfunction) and that each operates over the common parametric
+ domain.
+
+ Also, the `set parametric` function implies a new range of values. Whereas
+ the normal f(x) and f(x,y) style plotting assume an xrange and yrange (and
+ zrange), the parametric mode additionally specifies a trange, urange, and
+ vrange. These ranges may be set directly with `set trange`, `set urange`,
+ and `set vrange`, or by specifying the range on the `plot` or `splot`
+ commands. Currently the default range for these parametric variables is
+ [-5:5]. Setting the ranges to something more meaningful is expected.
+3 plot
+?commands show plot
+?show plot
+ The `show plot` command shows the current plotting command as it results
+ from the last `plot` and/or `splot` and possible subsequent `replot` commands.
+
+ In addition, the `show plot add2history` command adds this current plot
+ command into the `history`. It is useful if you have used `replot` to add
+ more curves to the current plot and you want to edit the whole command now.
+3 pm3d
+?commands set pm3d
+?commands show pm3d
+?set pm3d
+?show pm3d
+?pm3d
+ pm3d is an `splot` style for drawing palette-mapped 3d and 4d data as
+ color/gray maps and surfaces. It uses a pm3d algorithm which allows plotting
+ gridded as well as non-gridded data without preprocessing, even when the data
+ scans do not have the same number of points.
+
+ Drawing of color surfaces is available on terminals supporting filled colored
+ polygons with color mapping specified by `palette`. Currently supported
+ terminals include
+
+ Screen terminals:
+ OS/2 Presentation Manager
+ X11
+ Linux VGA (vgagl)
+ GGI
+ Windows
+ AquaTerm (Mac OS X)
+ wxWidgets (wxt)
+ Files:
+ PostScript
+ pslatex, pstex, epslatex
+ gif, png, jpeg
+ (x)fig
+ tgif
+ cgm
+ pdf
+ svg
+ emf
+
+ Let us first describe how a map/surface is drawn. The input data come from an
+ evaluated function or from an `splot data file`. Each surface consists of a
+ sequence of separate scans (isolines). The pm3d algorithm fills the region
+ between two neighbouring points in one scan with another two points in the
+ next scan by a gray (or color) according to z-values (or according to an
+ additional 'color' column, see help for `using`) of these 4 corners; by default
+ the 4 corner values are averaged, but this can be changed by the option
+ `corners2color`. In order to get a reasonable surface, the neighbouring scans
+ should not cross and the number of points in the neighbouring scans should not
+ differ too much; of course, the best plot is with scans having same number of
+ points. There are no other requirements (e.g. the data need not be gridded).
+ Another advantage is that the pm3d algorithm does not draw anything outside of
+ the input (measured or calculated) region.
+
+ Surface coloring works with the following input data:
+
+ 1. splot of function or of data file with one or three data columns: The
+ gray/color scale is obtained by mapping the averaged (or `corners2color`)
+ z-coordinate of the four corners of the above-specified quadrangle into the
+ range [min_color_z,max_color_z] of `zrange` or `cbrange` providing a gray value
+ in the range [0:1]. This value can be used directly as the gray for gray maps.
+ The normalized gray value can be further mapped into a color---see `set palette`
+ for the complete description.
+
+ 2. splot of data file with two or four data columns: The gray/color value is
+ obtained by using the last-column coordinate instead of the z-value, thus
+ allowing the color and the z-coordinate be mutually independent. This can be
+ used for 4d data drawing.
+
+ Other notes:
+
+ 1. The term 'scan' referenced above is used more among physicists than the
+ term 'iso_curve' referenced in gnuplot documentation and sources. You measure
+ maps recorded one scan after another scan, that's why.
+
+ 2. The 'gray' or 'color' scale is a linear mapping of a continuous variable
+ onto a smoothly varying palette of colors. The mapping is shown in a
+ rectangle next to the main plot. This documentation refers to this as a
+ "colorbox", and refers to the indexing variable as lying on the colorbox axis.
+ See `set colorbox`, `set cbrange`.
+
+ 3. To use pm3d coloring to generate a two-dimensional plot rather than a 3D
+ surface, use `set view map` or `set pm3d map`.
+
+ Syntax (the options can be given in any order):
+ set pm3d {
+ { at <bst combination> }
+ { interpolate <steps in scan>,<steps between scans> }
+ { scansautomatic | scansforward | scansbackward | depthorder }
+ { flush { begin | center | end } }
+ { ftriangles | noftriangles }
+ { clip1in | clip4in }
+ { corners2color { mean|geomean|median|min|max|c1|c2|c3|c4 } }
+ { hidden3d <linestyle> | nohidden3d }
+ { implicit | explicit }
+ { map }
+ }
+ show pm3d
+ unset pm3d
+
+ Color surface is drawn if data or function `style` is set to pm3d globally or
+ via 'with' option, or if the option `implicit` is on---then the pm3d surface
+ is combined with the line surface mesh. See bottom of this section for mode
+ details.
+
+ Color surface can be drawn at the base or top (then it is a gray/color planar
+ map) or at z-coordinates of surface points (gray/color surface). This is
+ defined by the `at` option with a string of up to 6 combinations of `b`, `t`
+ and `s`. For instance, `at b` plots at bottom only, `at st` plots firstly
+ surface and then top map, while `at bstbst` will never by seriously used.
+
+ Colored quadrangles are plotted one after another. When plotting surfaces
+ (`at s`), the later quadrangles overlap (overdraw) the previous ones.
+ (Gnuplot is not virtual reality tool to calculate intersections of filled
+ polygon meshes.) You may try to switch between `scansforward` and
+ `scansbackward` to force the first scan of the data to be plotted first or
+ last. The default is `scansautomatic` where gnuplot makes a guess about scans
+ order. On the other hand, the `depthorder` option completely reorders the
+ qudrangles. The rendering is performed after a depth sorting, which allows to
+ visualize even complicated surfaces; see `pm3d depthorder` for more
+ details.
+
+ If two subsequent scans do not have same number of points, then it has to be
+ decided whether to start taking points for quadrangles from the beginning of
+ both scans (`flush begin`), from their ends (`flush end`) or to center them
+ (`flush center`). Note, that `flush (center|end)` are incompatible with
+ `scansautomatic`: if you specify `flush center` or `flush end` and
+ `scansautomatic` is set, it is silently switched to `scansforward`.
+
+ If two subsequent scans do not have the same number of points, the option
+ `ftriangles` specifies whether color triangles are drawn at the scan tail(s)
+ where there are not enough points in either of the scan. This can be used to
+ draw a smooth map boundary.
+
+ Clipping with respect to x, y coordinates of quadrangles can be done in two
+ ways. `clip1in`: all 4 points of each quadrangle must be defined and at least
+ 1 point of the quadrangle must lie in the x and y ranges. `clip4in`: all 4
+ points of each quadrangle must lie in the x and y ranges.
+
+ There is a single gray/color value associated to each drawn pm3d quadrangle
+ (no smooth color change among vertices). The value is calculated from
+ z-coordinates from the surrounding corners according to `corners2color
+ <option>`. The options 'mean' (default), 'geomean' and 'median' produce
+ various kinds of surface color smoothing, while options 'min' and 'max' choose
+ minimal or maximal value, respectively. This may not be desired for pixel
+ images or for maps with sharp and intense peaks, in which case the options
+ 'c1', 'c2', 'c3' or 'c4' can be used instead to assign the quadrangle color
+ based on the z-coordinate of only one corner. Some experimentation may be
+ needed to determine which corner corresponds to 'c1', as the orientation
+ depends on the drawing direction. Because the pm3d algorithm does not extend
+ the colored surface outside the range of the input data points, the 'c<j>'
+ coloring options will result in pixels along two edges of the grid not
+ contributing to the color of any quadrangle. For example, applying the pm3d
+ algorithm to the 4x4 grid of data points in script `demo/pm3d.dem` (please have
+ a look) produces only (4-1)x(4-1)=9 colored rectangles.
+
+ Another drawing algorithm, which would draw quadrangles around a given node
+ by taking corners from averaged (x,y)-coordinates of its surrounding 4 nodes
+ while using node's color, could be implemented in the future. This is already
+ done for drawing images (2D grids) via `image` and `rgbimage` styles.
+
+ Notice that ranges of z-values and color-values for surfaces are adjustable
+ independently by `set zrange`, `set cbrange`, as well as `set log` for z or
+ cb. Maps can be adjusted by the cb-axis only; see also `set view map` and
+ `set colorbox`.
+
+ The option `hidden3d` takes as the argument a linestyle which must be created
+ by `set style line ...`. (The style need not to be present when setting pm3d,
+ but it must be present when plotting). If set, lines are drawn using the
+ specified line style, taking into account hidden line removal. This is by
+ far more efficient than using the command `set hidden3d` as it doesn't really
+ calculate hidden line removal, but just draws the filled polygons in the
+ correct order. So the recommended choice when using pm3d is
+ set pm3d at s hidden3d 100
+ set style line 100 lt 5 lw 0.5
+ unset hidden3d
+ unset surf
+ splot x*x+y*y
+
+ There used to be an option {transparent|solid} to this command. Now
+ you get the same effect from `set grid {front|layerdefault}`,
+ respectively.
+
+ The `set pm3d map` is an abbreviation for `set pm3d at b`; `set view map`;
+ `set style data pm3d`; `set style func pm3d`;.
+ It is used for backwards compatibility, when `set view map` was not available.
+ Take care that you properly use `zrange` and `cbrange` for input data point
+ filtering and color range scaling, respectively; and also `set (no)surface`
+ seems to have a (side?) effect.
+
+ The option `interpolate` will interpolate grid points into a finer mesh, and
+ color each quadrangle appropriately. For data files, this will smoothen the
+ color surface, and enhance spikes in a color surface. For functions,
+ interpolation makes little sense, except to trade off precision for memory.
+ It would usually make more sense to use `samples` and `isosamples` when working
+ with functions.
+
+ The coloring setup as well as the color box drawing are determined by
+ `set palette`. There can be only one palette for the current plot. Drawing
+ of several surfaces with different palettes can be achieved by `multiplot`
+ with fixed `origin` and `size`; don't forget to use `set palette maxcolors`
+ when your terminal is running out of available colors.
+
+ On gnuplot start-up, mode is `explicit`. For historical and thus compatibility
+ reasons, commands `set pm3d;` (i.e. no options) and `set pm3d at X ...` (i.e.
+ `at` is the first option) sets mode `implicit`. Further, `set pm3d;` sets up
+ the other options to their default.
+
+ If the option `implicit` is on, all surface plots will be plotted additionally
+ to the default type, e.g.
+ splot 'fred.dat' with lines, 'lola.dat' with lines
+ would give both plots (meshes) additionally to a pm3d surface. That's what you
+ are used to after `set pm3d;`.
+
+ If the option `explicit` is on (or `implicit` is off) only plots specified
+ by the `with pm3d` attribute are plotted with a pm3d surface, e.g.:
+ splot 'fred.dat' with lines, 'lola.dat' with pm3d
+ would plot 'fred.dat' with lines (and only lines) and 'lola.dat' with
+ a pm3d surface.
+
+ If you set the default data or function style to `pm3d`, e.g.:
+ set style data pm3d
+ then the options `implicit` and `explicit` have no effect.
+
+ Note that when plotting several plots, they are plotted in the order given
+ on the command line. This can be of interest especially for filled surfaces
+ which can overwrite and therefore hide part of earlier plots.
+
+ If `with pm3d` is specified in the `splot` command line, then it accepts the
+ 'at' option. The following plots draw three color surfaces at different
+ altitudes:
+ set border 4095
+ set pm3d at s
+ splot 10*x with pm3d at b, x*x-y*y, x*x+y*y with pm3d at t
+
+ See also help for `set palette`, `set cbrange`, `set colorbox`, `x11 pm3d`
+ and definitely the demo file `demo/pm3d.dem`.
+4 depthorder
+?commands set pm3d depthorder
+?set pm3d depthorder
+?pm3d depthorder
+?depthorder
+ By default the quadrangles making up a pm3d solid surface are rendered in the
+ order they are encountered along the surface grid points. This order may be
+ controlled by the options `scansautomatic`|`scansforward`|`scansbackward`.
+ These scan options are not in general compatible with hidden-surface removal.
+
+ Gnuplot does not do true hidden surface removal for solid surfaces, but often
+ it is sufficient to render the component quadrangles in order from furthest
+ to closest. This mode may be selected using the options
+ set pm3d depthorder hidden3d
+ The `depthorder` option orders the solid quadrangles; the `hidden3d` option
+ similarly orders the bounding lines (if drawn). Note that the global option
+ `set hidden3d` does not affect pm3d surfaces.
+3 palette
+?commands set palette
+?commands show palette
+?set palette
+?show palette
+?palette
+ Palette is a color storage for use by `pm3d`, filled color contours or
+ polygons, color histograms, color gradient background, and whatever it is
+ or it will be implemented... Here it stands for a palette of smooth
+ "continuous" colors or grays, but let's call it just a palette.
+
+ Color palettes require terminal entries for filled color polygons and
+ palettes of smooth colors, are currently available for terminals listed in
+ help for `set pm3d`. The range of color values are adjustable independently by
+ `set cbrange` and `set log cb`. The whole color palette is
+ visualized in the `colorbox`.
+
+ Syntax:
+ set palette
+ set palette {
+ { gray | color }
+ { gamma <gamma> }
+ { rgbformulae <r>,<g>,<b>
+ | defined { ( <gray1> <color1> {, <grayN> <colorN>}... ) }
+ | file '<filename>' {datafile-modifiers}
+ | functions <R>,<G>,<B>
+ }
+ { model { RGB | HSV | CMY | YIQ | XYZ } }
+ { positive | negative }
+ { nops_allcF | ps_allcF }
+ { maxcolors <maxcolors> }
+ }
+ show palette
+ show palette palette <n> {{float | int}}
+ show palette gradient
+ show palette fit2rgbformulae
+ show palette rgbformulae
+ show palette colornames
+
+ `set palette` (i.e. without options) sets up the default values.
+ Otherwise, the options can be given in any order.
+ `show palette` shows the current palette properties.
+
+ `show palette gradient` displays the gradient defining the palette (if
+ appropriate). `show palette rgbformulae` prints the available fixed gray -->
+ color transformation formulae. `show palette colornames` prints the
+ implemented color names.
+
+ `show palette palette <n>` prints to screen or to the file given by
+ `set output` table of RGB triplets calculated for the current palette settings
+ and a palette having <n> discrete colors. The default wide table can be
+ limited to 3 columns of r,g,b float values [0..1] or integer values [0..255]
+ by options float or int, respectively. This way, the current gnuplot color
+ palette can be loaded into other imaging applications, for example Octave.
+ Additionally to this textual list of RGB table, you can enjoy command `test
+ palette` to draw graphically the R,G,B profiles for the current palette.
+
+ The following options determine the coloring properties.
+
+ Figure using this palette can be `gray` or `color`. For instance, in `pm3d`
+ color surfaces the gray of each small spot is obtained by mapping the averaged
+ z-coordinate of the 4 corners of surface quadrangles into the range
+ [min_z,max_z] providing range of grays [0:1]. This value can be used directly
+ as the gray for gray maps. The color map requires a transformation gray -->
+ (R,G,B), i.e. a mapping [0:1] --> ([0:1],[0:1],[0:1]).
+
+ Basically two different types of mappings can be used: Analytic formulae to
+ convert gray to color, or discrete mapping tables which are interpolated.
+ `palette rgbformulae` and `palette functions` use analytic formulae whereas
+ `palette defined` and `palette file` use interpolated tables. `palette
+ rgbformulae` reduces the size of postscript output to a minimum.
+
+ The command `show palette fit2rgbformulae` finds the best matching `set
+ palette rgbformulae` for the current `set palette`. Naturally, it makes sense
+ to use it for non-rgbformulae palettes. This command can be found useful
+ mainly for external programs using the same rgbformulae definition of palettes
+ as gnuplot, like zimg (
+^ <a href="http://zimg.sourceforge.net">
+ http://zimg.sourceforge.net
+^ </a>
+ ).
+
+ `set palette gray` switches to a gray only palette. `set palette rgbformulae`,
+ `set palette defined`, `set palette file` and `set palette functions` switch
+ to a color mapping. `set palette color` is an easy way to switch back from the
+ gray palette to the last color mapping.
+
+ Automatic gamma correction via `set palette gamma <gamma>` can be done for
+ gray maps only (`set palette gray`). Linear mapping to gray is for gamma
+ equals 1, see `test palette`. Gamma is ignored for color mappings.
+
+ Most terminals support only discrete number of colors (e.g. 256 colors in
+ gif). All entries of the palette remaining after the default gnuplot linetype
+ colors declaration are allocated for pm3d by default. Then `multiplot` could
+ fail if there are no more color positions in the terminal available. Then you
+ should use `set palette maxcolors <maxcolors>` with a reasonably small value.
+ This option can also be used to separate levels of z=constant in discrete
+ steps, thus to emulate filled contours. Default value of 0 stays for
+ allocating all remaining entries in the terminal palette or for to use exact
+ mapping to RGB.
+
+ RGB color space might not be the most useful color space to work in. For that
+ reason you may change the color space with `model` to one of `RGB`, `HSV`,
+ `CMY`, `YIQ` and `XYZ`. Using color names for `set palette defined` tables
+ and a color space other than RGB will result in funny colors. All explanation
+ have been written for RGB color space, so please note, that `R` can be `H`,
+ `C`, `Y`, or `X`, depending on the actual color space (`G` and `B`
+ accordingly).
+
+ All values for all color spaces are limited to [0,1].
+
+ RGB stands for Red, Green and Blue; CMY stands for Cyan, Magenta and Yellow;
+ HSV stands for Hue, Saturation, and Value; YIQ is the color model used by
+ the U.S. Commercial Color Television Broadcasting, it is basically an RGB
+ recoding with downward compatibility for black and white television;
+ XYZ are the three primary colors of the color model defined by the 'Commission
+ Internationale de l'Eclairage' (CIE).
+ For more information on color models see:
+^ <a href="http://www.cs.rit.edu/~ncs/color/glossary.htm">
+ http://www.cs.rit.edu/~ncs/color/glossary.htm
+^ </a>
+ and
+^ <a href="http://cs.fit.edu/wds/classes/cse5255/cse5255/davis/index.html">
+ http://cs.fit.edu/wds/classes/cse5255/cse5255/davis/index.html
+^ </a>
+
+4 rgbformulae
+?commands set palette rgbformulae
+?set palette rgbformulae
+?palette rgbformulae
+?rgbformulae
+=colors
+ For `rgbformulae` three suitable mapping functions have
+ to be chosen. This is done via `rgbformulae <r>,<g>,<b>`. The available
+ mapping functions are listed by `show palette rgbformulae`. Default is
+ `7,5,15`, some other examples are `3,11,6`, `21,23,3` or `3,23,21`. Negative
+ numbers, like `3,-11,-6`, mean inverted color (i.e. 1-gray passed into the
+ formula, see also `positive` and `negative` options below).
+
+ Some nice schemes in RGB color space
+ 7,5,15 ... traditional pm3d (black-blue-red-yellow)
+ 3,11,6 ... green-red-violet
+ 23,28,3 ... ocean (green-blue-white); try also all other permutations
+ 21,22,23 ... hot (black-red-yellow-white)
+ 30,31,32 ... color printable on gray (black-blue-violet-yellow-white)
+ 33,13,10 ... rainbow (blue-green-yellow-red)
+ 34,35,36 ... AFM hot (black-red-yellow-white)
+
+ A full color palette in HSV color space
+ 3,2,2 ... red-yellow-green-cyan-blue-magenta-red
+
+ Please note that even if called `rgbformulae` the formulas might actually
+ determine the <H>,<S>,<V> or <X>,<Y>,<Z> or ... color components as usual.
+
+ Use `positive` and `negative` to invert the figure colors.
+^ <a name="positive"></a>
+^ <a name="negative"></a>
+
+ Note that it is possible to find a set of the best matching rgbformulae for any
+ other color scheme by the command
+ show palette fit2rgbformulae
+4 defined
+?commands set palette defined
+?set palette defined
+?palette defined
+=colors
+ Gray-to-rgb mapping can be manually set by use of `palette defined`: A color gradient
+ is defined and used to give the rgb values. Such a gradient is a piecewise
+ linear mapping from gray values in [0,1] to the RGB space [0,1]x[0,1]x[0,1].
+ You have to specify the gray values and the corresponding RGB values in
+ between a linear interpolation shall take place:
+
+ Syntax:
+ set palette defined { ( <gray1> <color1> {, <grayN> <colorN>}... ) }
+
+ <grayX> are gray values which are mapped to [0,1] and <colorX> are the
+ corresponding rgb colors. The color can be specified in three different
+ ways:
+
+ <color> := { <r> <g> <b> | '<color-name>' | '#rrggbb' }
+
+ Either by three numbers (each in [0,1]) for red, green and blue, separated by
+ whitespace, or the name of the color in quotes or X style color specifiers
+ also in quotes. You may freely mix the three types in a gradient definition,
+ but the named color "red" will be something strange if RGB is not selected
+ as color space. Use `show palette colornames` for a list of known color
+ names.
+
+ Please note, that even if written as <r>, this might actually be the
+ <H> component in HSV color space or <X> in CIE-XYZ space, or ...
+ depending on the selected color model.
+
+ The <gray> values have to form an ascending sequence of real numbers; the
+ sequence will be automatically rescaled to [0,1].
+
+ `set palette defined` (without a gradient definition in braces) switches to
+ RGB color space and uses a preset full-spectrum color gradient.
+ Use `show palette gradient` to display the gradient.
+
+ Examples:
+
+ To produce a gray palette (useless but instructive) use:
+ set palette model RGB
+ set palette defined ( 0 "black", 1 "white" )
+
+ To produce a blue yellow red palette use (all equivalent):
+ set palette defined ( 0 "blue", 1 "yellow", 2 "red" )
+ set palette defined ( 0 0 0 1, 1 1 1 0, 2 1 0 0 )
+ set palette defined ( 0 "#0000ff", 1 "#ffff00", 2 "#ff0000" )
+
+ To produce some rainbow-like palette use:
+ set palette defined ( 0 "blue", 3 "green", 6 "yellow", 10 "red" )
+
+ Full color spectrum within HSV color space:
+ set palette model HSV
+ set palette defined ( 0 0 1 1, 1 1 1 1 )
+ set palette defined ( 0 0 1 0, 1 0 1 1, 6 0.8333 1 1, 7 0.8333 0 1)
+
+ To produce a palette with few colors only use:
+ set palette model RGB maxcolors 4
+ set palette defined ( 0 "blue", 1 "green", 2 "yellow", 3 "red" )
+
+ 'Traffic light' palette (non-smooth color jumps at gray = 1/3 and 2/3).
+ set palette model RGB
+ set palette defined (0 "dark-green", 1 "green", 1 "yellow", \
+ 2 "dark-yellow", 2 "red", 3 "dark-red" )
+
+4 functions
+?commands set palette functions
+?set palette functions
+?palette functions
+ Use `set palette functions <Rexpr>, <Gexpr>, <Bexpr>` to define three formulae
+ for the R(gray), G(gray) and B(gray) mapping. The three formulae may depend
+ on the variable `gray` which will take values in [0,1] and should also
+ produce values in [0,1].
+ Please note that <Rexpr> might be a formula for the H-value if HSV color
+ space has been chosen (same for all other formulae and color spaces).
+
+ Examples:
+
+ To produce a full color palette use:
+ set palette model HSV functions gray, 1, 1
+
+ A nice black to gold palette:
+ set palette model XYZ functions gray**0.35, gray**0.5, gray**0.8
+
+ A gamma-corrected black and white palette
+ gamma = 2.2
+ color(gray) = gray**(1./gamma)
+ set palette model RGB functions color(gray), color(gray), color(gray)
+
+4 file
+?commands set palette file
+?set palette file
+?palette file
+ `set palette file` is basically a `set palette defined (<gradient>)` where
+ <gradient> is read from a datafile. Either 4 columns (gray,R,G,B) or
+ just three columns (R,G,B) have to be selected via the `using` data file
+ modifier. In the three column case, the line number will be used as gray.
+ The gray range is automatically rescaled to [0,1]. The file is read as a
+ normal data file, so all datafile modifiers can be used.
+ Please note, that `R` might actually be e.g. `H` if HSV color space is
+ selected.
+
+ As usual <filename> may be `'-'` which means that the data follow the command
+ inline and are terminated by a single `e` on a line of its own.
+
+ Use `show palette gradient` to display the gradient.
+
+ Examples:
+
+ Read in a palette of RGB triples each in range [0,255]:
+ set palette file 'some-palette' using ($1/255):($2/255):($3/255)
+
+ Equidistant rainbow (blue-green-yellow-red) palette:
+ set palette model RGB file "-"
+ 0 0 1
+ 0 1 0
+ 1 1 0
+ 1 0 0
+ e
+
+ Binary palette files are supported as well, see `binary general`. Example:
+ put 64 triplets of R,G,B doubles into file palette.bin and load it by
+ set palette file "palette.bin" binary record=64 using 1:2:3
+
+
+4 gamma correction
+?commands set palette gamma-correction
+?set palette gamma-correction
+?palette gamma-correction
+?gamma-correction
+ For gray mappings gamma correction can be turned on by `set palette gamma
+ <gamma>`. <gamma> defaults to 1.5 which is quite suitable for most
+ terminals.
+
+ For color mappings no automatic gamma correction is done by gnuplot. However,
+ you may easily implement gamma correction. Here is an example for a gray
+ scale image by use of explicit functions for the red, green and blue component
+ with slightly different values of gamma
+
+ Example:
+ set palette model RGB
+ set palette functions gray**0.64, gray**0.67, gray**0.70
+
+ To use gamma correction with interpolated gradients specify intermediate
+ gray values with appropriate colors. Instead of
+
+ set palette defined ( 0 0 0 0, 1 1 1 1 )
+
+ use e.g.
+
+ set palette defined ( 0 0 0 0, 0.5 .73 .73 .73, 1 1 1 1 )
+
+ or even more intermediate points until the linear interpolation fits the
+ "gamma corrected" interpolation well enough.
+
+4 postscript
+?commands set palette postscript
+?set palette postscript
+ In order to reduce the size of postscript files, the gray value and not all
+ three calculated r,g,b values are written to the file. Therefore the
+ analytical formulae are coded directly in the postscript language as a header
+ just before the pm3d drawing, see /g and /cF definitions. Usually, it makes
+ sense to write therein definitions of only the 3 formulae used. But for
+ multiplot or any other reason you may want to manually edit the
+ transformations directly in the postscript file. This is the default option
+ `nops_allcF`. Using the option `ps_allcF` writes postscript definitions of
+ all formulae. This you may find interesting if you want to edit the
+ postscript file in order to have different palettes for different surfaces
+ in one graph. Well, you can achieve this functionality by `multiplot` with
+ fixed `origin` and `size`.
+
+ If pm3d map has been plotted from gridded or almost regular data with an
+ output to a postscript file, then it is possible to reduce the size of this
+ postscript file up to at about 50% by the enclosed awk script
+ `pm3dCompress.awk`. This you may find interesting if you intend to keep the
+ file for including it into your publication or before downloading a very large
+ file into a slow printer. Usage:
+ awk -f pm3dCompress.awk thefile.ps >smallerfile.ps
+
+ If pm3d map has been plotted from rectangular gridded data with an output
+ to a postscript file, then it is possible to reduce the file size even more
+ by the enclosed awk script `pm3dConvertToImage.awk`. Usage:
+ awk -f pm3dConvertToImage.awk <thefile.ps >smallerfile.ps
+
+ You may manually change the postscript output from gray to color and vice
+ versa and change the definition of <maxcolors>.
+4 colornames
+?colornames
+?show palette colornames
+?show colornames
+ Gnuplot knows a limited number of color names. You can use these to define
+ the color range spanned by a pm3d palette, or to assign a terminal-independent
+ color to a particular linetype or linestyle. To see the list of known color
+ names, use the command `show palette colornames`.
+ See `set palette`, `linestyle`.
+3 pointsize
+?commands set pointsize
+?commands show pointsize
+?set pointsize
+?show pointsize
+?pointsize
+ The `set pointsize` command scales the size of the points used in plots.
+
+ Syntax:
+ set pointsize <multiplier>
+ show pointsize
+
+ The default is a multiplier of 1.0. Larger pointsizes may be useful to
+ make points more visible in bitmapped graphics.
+
+ The pointsize of a single plot may be changed on the `plot` command.
+ See `plot with` for details.
+
+ Please note that the pointsize setting is not supported by all terminal
+ types.
+3 polar
+?commands set polar
+?commands unset polar
+?commands show polar
+?set polar
+?unset polar
+?show polar
+?polar
+?nopolar
+ The `set polar` command changes the meaning of the plot from rectangular
+ coordinates to polar coordinates.
+
+ Syntax:
+ set polar
+ unset polar
+ show polar
+
+ There have been changes made to polar mode in version 3.7, so that scripts
+ for `gnuplot` versions 3.5 and earlier will require modification. The main
+ change is that the dummy variable t is used for the angle so that the x and
+ y ranges can be controlled independently. Other changes are:
+ 1) tics are no longer put along the zero axes automatically
+ ---use `set xtics axis nomirror`; `set ytics axis nomirror`;
+ 2) the grid, if selected, is not automatically polar
+ ---use `set grid polar`;
+ 3) the grid is not labelled with angles
+ ---use `set label` as necessary.
+
+ In polar coordinates, the dummy variable (t) is an angle. The default range
+ of t is [0:2*pi], or, if degree units have been selected, to [0:360] (see
+ `set angles`).
+
+ The command `unset polar` changes the meaning of the plot back to the default
+ rectangular coordinate system.
+
+ The `set polar` command is not supported for `splot`s. See the `set mapping`
+ command for similar functionality for `splot`s.
+
+ While in polar coordinates the meaning of an expression in t is really
+ r = f(t), where t is an angle of rotation. The trange controls the domain
+ (the angle) of the function, and the x and y ranges control the range of the
+ graph in the x and y directions. Each of these ranges, as well as the
+ rrange, may be autoscaled or set explicitly. See `set xrange` for details
+ of all the `ranges` commands.
+
+ Example:
+ set polar
+ plot t*sin(t)
+ plot [-2*pi:2*pi] [-3:3] [-3:3] t*sin(t)
+
+ The first `plot` uses the default polar angular domain of 0 to 2*pi. The
+ radius and the size of the graph are scaled automatically. The second `plot`
+ expands the domain, and restricts the size of the graph to [-3:3] in both
+ directions.
+
+ You may want to `set size square` to have `gnuplot` try to make the aspect
+ ratio equal to unity, so that circles look circular.
+ See also
+^ <a href="http://www.gnuplot.info/demo/polar.html">
+ polar demos (polar.dem)
+^ </a>
+ and
+^ <a href="http://www.gnuplot.info/demo/poldat.html">
+ polar data plot (poldat.dem).
+^ </a>
+3 print
+?commands set print
+?commands show print
+?set print
+?show print
+ The `set print` command redirects the output of the `print` command to a file.
+
+ Syntax:
+ set print
+ set print "-"
+ set print "<filename>"
+ set print "<filename>" append
+ set print "|<shell_command>"
+
+ Without "<filename>", the output file is restored to <STDERR>. The <filename>
+ "-" means <STDOUT>. The `append` flag causes the file to be opened in append
+ mode. A <filename> starting with "|" is opened as a pipe to the
+ <shell_command> on platforms that support piping.
+3 object
+?object
+?rectangle
+?commands set object
+?commands show object
+?commands set object rectangle
+?commands show object rectangle
+?set object
+?show object
+?set object rectangle
+?show object rectangle
+ This command defines a single object, which will appear in all subsequent
+ 2D plots. You may define as many objects as you like. Currently the only
+ object type supported is `rectangle`.
+ Each rectangle is specified by a pair of points that define diagonal vertices.
+ A default set of style properties (fill, color, border) are inherited from
+ those set by the command `set style rectangle`, but each rectangle can also be
+ given individual style properties.
+
+ Syntax:
+ set object <index> rectangle
+ {from <position> {to|rto} <position> |
+ center <position> size <w>,<h> |
+ at <position> size <w>,<h>}
+ {front|back|behind} {fc|fillcolor <colorspec>} {fs <fillstyle>}
+ {default} {lw|linewidth <width>}
+
+ The position of the rectangle may be specified by giving the position of two
+ diagonal corners (bottom left and top right) or by giving the position of the
+ center followed by the width and the height. In either case the positions
+ may be given in axis, graph, or screen coordinates. See `coordinates`.
+ The options `at` and `center` are synonyms.
+
+ Setting `front` will draw the rectangle in front of all plot elements, but
+ behind any labels that are also marked `front`. Setting `back` will place the
+ rectangle behind all plot curves and labels. Setting `behind` will place the
+ rectangle behind everything including the axes and `back` rectangles, and can
+ be used to provide a colored background for the entire graph or page.
+
+ The fill color of the rectangle is taken from the <colorspec>. `fillcolor`
+ may be abbreviated `fc`. The fill style is taken from <fillstyle>.
+ See `colorspec` and `fillstyle`. If the keyword `default` is given,
+ these properties are inherited from the default settings of at the time a plot
+ is drawn. See `set style rectangle`.
+
+ Examples:
+ # Force the entire area enclosed by the axes to have background color cyan
+ set object 1 rect from graph 0, graph 0 to graph 1, graph 1 back
+ set object 1 rect fc rgb "cyan" fillstyle solid 1.0
+
+ # Position a red square with lower left at 0,0 and upper right at 2,3
+ set object 2 rect from 0,0 to 2,3 fc lt 1
+
+ # Position an empty rectangle (no fill) with a blue border
+ set object 3 rect from 0,0 to 2,3 fs empty border 3
+
+ # Return fill and color to the default style but leave vertices unchanged
+ set object 2 rect default
+
+3 rmargin
+?commands set rmargin
+?set rmargin
+?rmargin
+ The command `set rmargin` sets the size of the right margin.
+ Please see `set margin` for details.
+3 rrange
+?commands set rrange
+?commands show rrange
+?set rrange
+?show rrange
+?rrange
+ The `set rrange` command sets the range of the radial coordinate for a
+ graph in polar mode. Please see `set xrange` for details.
+3 samples
+?commands set samples
+?commands show samples
+?set samples
+?show samples
+?samples
+ The sampling rate of functions, or for interpolating data, may be changed
+ by the `set samples` command.
+
+ Syntax:
+ set samples <samples_1> {,<samples_2>}
+ show samples
+
+ By default, sampling is set to 100 points. A higher sampling rate will
+ produce more accurate plots, but will take longer. This parameter has no
+ effect on data file plotting unless one of the interpolation/approximation
+ options is used. See `plot smooth` re 2-d data and `set cntrparam` and
+ `set dgrid3d` re 3-d data.
+
+ When a 2-d graph is being done, only the value of <samples_1> is relevant.
+
+ When a surface plot is being done without the removal of hidden lines, the
+ value of samples specifies the number of samples that are to be evaluated for
+ the isolines. Each iso-v line will have <sample_1> samples and each iso-u
+ line will have <sample_2> samples. If you only specify <samples_1>,
+ <samples_2> will be set to the same value as <samples_1>. See also
+ `set isosamples`.
+3 size
+?commands set size
+?commands show size
+?set size
+?show size
+?size
+?aspect ratio
+ Syntax:
+ set size {{no}square | ratio <r> | noratio} {<xscale>,<yscale>}
+ show size
+
+ The <xscale> and <yscale> values are scale factors for the size of the plot,
+ which includes the graph, labels, and margins.
+
+ Important note:
+ In earlier versions of gnuplot, some terminal types used the values from
+ `set size` to control also the size of the output canvas; others did not.
+ In version 4.2 almost all terminals now follow the following convention:
+
+ `set term <terminal_type> size <XX>, <YY>` controls the size of the output
+ file, or `canvas`. Please see individual terminal documentation for allowed
+ values of the size parameters. By default, the plot will fill this canvas.
+
+ `set size <XX>, <YY>` scales the plot itself relative to the size of the
+ canvas. Scale values less than 1 will cause the plot to not fill the entire
+ canvas. Scale values larger than 1 will cause only a portion of the plot to
+ fit on the canvas. Please be aware that setting scale values larger than 1
+ may cause problems on some terminal types.
+
+ `ratio` causes `gnuplot` to try to create a graph with an aspect ratio of <r>
+ (the ratio of the y-axis length to the x-axis length) within the portion of
+ the plot specified by <xscale> and <yscale>.
+
+ The meaning of a negative value for <r> is different. If <r>=-1, gnuplot
+ tries to set the scales so that the unit has the same length on both the x
+ and y axes (suitable for geographical data, for instance). If <r>=-2, the
+ unit on y has twice the length of the unit on x, and so on.
+
+ The success of `gnuplot` in producing the requested aspect ratio depends on
+ the terminal selected. The graph area will be the largest rectangle of
+ aspect ratio <r> that will fit into the specified portion of the output
+ (leaving adequate margins, of course).
+
+ `square` is a synonym for `ratio 1`.
+
+ Both `noratio` and `nosquare` return the graph to the default aspect ratio
+ of the terminal, but do not return <xscale> or <yscale> to their default
+ values (1.0).
+
+ `ratio` and `square` have no effect on 3-d plots, but do affect 3D projections
+ created using `set view map`. Similarly `set view equal` forces the
+ x and y axes of a 3D onto the same scale.
+
+ Examples:
+
+ To set the size so that the plot fills the available canvas:
+ set size 1,1
+
+ To make the graph half size and square use:
+ set size square 0.5,0.5
+
+ To make the graph twice as high as wide use:
+ set size ratio 2
+
+ See also
+^ <a href="http://www.gnuplot.info/demo/airfoil.html">
+ airfoil demo.
+^ </a>
+3 style
+?set style
+?show style
+?unset style
+^ <a name="set style <style>"></a>
+ Default plotting styles are chosen with the `set style data` and
+ `set style function` commands. See `plot with` for information about how to
+ override the default plotting style for individual functions and data sets.
+ See `plotting styles` for a complete list of styles.
+
+ Syntax:
+ set style function <style>
+ set style data <style>
+ show style function
+ show style data
+
+ Default styles for specific plotting elements may also be set.
+
+ Syntax:
+ set style arrow <n> <arrowstyle>
+ set style fill <fillstyle>
+ set style histogram <histogram style options>
+ set style line <n> <linestyle>
+
+4 set style arrow
+?commands set style arrow
+?commands unset style arrow
+?commands show style arrow
+?set style arrow
+?unset style arrow
+?show style arrow
+?arrowstyle
+^ <a name="arrowtype"></a>
+^ <a name="arrowwidth"></a>
+ Each terminal has a default set of arrow and point types, which can be seen
+ by using the command `test`. `set style arrow` defines a set of arrow types
+ and widths and point types and sizes so that you can refer to them later by
+ an index instead of repeating all the information at each invocation.
+
+ Syntax:
+ set style arrow <index> default
+ set style arrow <index> {nohead | head | heads}
+ {size <length>,<angle>{,<backangle>}}
+ {filled | empty | nofilled}
+ {front | back}
+ { {linestyle | ls <line_style>}
+ | {linetype | lt <line_type>}
+ {linewidth | lw <line_width} }
+ unset style arrow
+ show style arrow
+
+ <index> is an integer that identifies the arrowstyle.
+
+ If `default` is given all arrow style parameters are set to their default
+ values.
+
+ If the linestyle <index> already exists, only the given parameters are
+ changed while all others are preserved. If not, all undefined values are
+ set to the default values.
+
+ Specifying `nohead` produces arrows drawn without a head---a line segment.
+ This gives you yet another way to draw a line segment on the plot. By
+ default, arrows have one head. Specifying `heads` draws arrow heads on both
+ ends of the line.
+
+ Head size can be controlled by `size <length>,<angle>` or
+ `size <length>,<angle>,<backangle>`, where `<length>` defines length of each
+ branch of the arrow head and `<angle>` the angle (in degrees) they make with
+ the arrow. `<Length>` is in x-axis units; this can be changed by `first`,
+ `second`, `graph`, `screen`, or `character` before the <length>; see
+ `coordinates` for details. `<Backangle>` only takes effect when `filled`
+ or `empty` is also used. Then, `<backangle>` is the angle (in degrees) the
+ back branches make with the arrow (in the same direction as `<angle>`).
+ The `fig` terminal has a restricted backangle function. It supports three
+ different angles. There are two thresholds: Below 70 degrees, the arrow head
+ gets an indented back angle. Above 110 degrees, the arrow head has an acute
+ back angle. Between these thresholds, the back line is straight.
+
+ Specifying `filled` produces filled arrow heads (if heads are used).
+ Filling is supported on filled-polygon capable terminals, see help of `pm3d`
+ for their list, otherwise the arrow heads are closed but not filled.
+ The same result (closed but not filled arrow head) is reached by specifying
+ `empty`. Further, filling and outline is obviously not supported on
+ terminals drawing arrows by their own specific routines, like `metafont`,
+ `metapost`, `latex` or `tgif`.
+
+ The line style may be selected from a user-defined list of line styles
+ (see `set style line`) or may be defined here by providing values for
+ `<line_type>` (an index from the default list of styles) and/or
+ `<line_width>` (which is a multiplier for the default width).
+
+ Note, however, that if a user-defined line style has been selected, its
+ properties (type and width) cannot be altered merely by issuing another
+ `set style arrow` command with the appropriate index and `lt` or `lw`.
+
+ If `front` is given, the arrows are written on top of the graphed data. If
+ `back` is given (the default), the arrow is written underneath the graphed
+ data. Using `front` will prevent a arrow from being obscured by dense data.
+
+ Examples:
+
+ To draw an arrow without an arrow head and double width, use:
+ set style arrow 1 nohead lw 2
+ set arrow arrowstyle 1
+
+ See also `set arrow` for further examples.
+
+4 set style data
+?commands set style data
+?commands show style data
+?set style data
+?show style data
+?data style
+ The `set style data` command changes the default plotting style for data
+ plots.
+
+ Syntax:
+ set style data <plotting-style>
+ show style data
+
+ See `plotting styles` for the choices. If no choice is given, the choices are
+ listed. `show style data` shows the current default data plotting style.
+4 set style fill
+?commands set style fill
+?commands show style fill
+?set style fill
+?show style fill
+?fillstyle
+ The `set style fill` command is used to set the style of boxes,
+ histograms, candlesticks and filledcurves.
+
+ Syntax:
+ set style fill {empty | solid {<density>} | pattern {<n>}}
+ {border {<linetype>} | noborder}
+
+ The default fillstyle is `empty`.
+
+ The `solid` option causes filling with a solid color, if the terminal
+ supports that. The <density> parameter specifies the intensity of the
+ fill color. At a <density> of 0.0, the box is empty, at <density> of 1.0,
+ the inner area is of the same color as the current linetype.
+ Some terminal types can vary the density continuously; others implement
+ only a few levels of partial fill. If no <density> parameter is given,
+ it defaults to 1.
+
+ The `pattern` option causes filling to be done with a fill pattern supplied
+ by the terminal driver. The kind and number of available fill patterns
+ depend on the terminal driver. If multiple datasets using filled boxes are
+ plotted, the pattern cycles through all available pattern types, starting
+ from pattern <n>, much as the line type cycles for multiple line plots.
+
+ The `empty` option causes filled boxes not to be filled. This is the default.
+
+ By default, `border`, the box is bounded by a solid line of the current
+ linetype. `border <lt>` specifies that a border is to be drawn using
+ linetype <lt>. `noborder` specifies that no bounding lines are drawn.
+4 set style function
+?commands set style function
+?commands show style function
+?set style function
+?show style function
+?function style
+ The `set style function` command changes the default plotting style for
+ function plots.
+
+ Syntax:
+ set style function <plotting-style>
+ show style function
+
+ See `plotting styles` for the choices. If no choice is given, the choices are
+ listed. `show style function` shows the current default function plotting
+ style.
+4 set style increment
+?commands set style increment
+?commands show style increment
+?set style increment
+?show style increment
+ Syntax:
+ set style increment {default|userstyles}
+ show style increment
+
+ By default, successive plots within the same graph will use successive
+ linetypes from the default set for the current terminal type.
+ However, choosing `set style increment user` allows you to step through
+ the user-defined line styles rather than through the default linetypes.
+
+ Example:
+
+ set style line 1 lw 2 lc rgb "gold"
+ set style line 2 lw 2 lc rgb "purple"
+ set style line 4 lw 1 lc rgb "sea-green"
+ set style increment user
+
+ plot f1(x), f2(x), f3(x), f4(x)
+
+ should plot functions f1, f2, f4 in your 3 newly defined line styles.
+ If a user-defined line style is not found then the corresponding default
+ linetype is used instead. E.g. in the example above, f3(x) will be plotted
+ using the default linetype 3.
+
+4 set style line
+?commands set style line
+?commands unset style line
+?commands show style line
+?set style line
+?unset style line
+?show style line
+?linestyle
+?linewidth
+ Each terminal has a default set of line and point types, which can be seen
+ by using the command `test`. `set style line` defines a set of line types
+ and widths and point types and sizes so that you can refer to them later by
+ an index instead of repeating all the information at each invocation.
+
+ Syntax:
+ set style line <index> default
+ set style line <index> {{linetype | lt} <line_type> | <colorspec>}
+ {{linecolor | lc} <colorspec>}
+ {{linewidth | lw} <line_width>}
+ {{pointtype | pt} <point_type>}
+ {{pointsize | ps} <point_size>}
+ {palette}
+ unset style line
+ show style line
+
+ If `default` is given all line style parameters are set to their default
+ values.
+
+ If the linestyle <index> already exists, only the given parameters are
+ changed while all others are preserved. If not, all undefined values are
+ set to the default values.
+
+ The line and point types are taken from the default types for the terminal
+ currently in use. The line width and point size are multipliers for the
+ default width and size (but note that <point_size> here is unaffected by
+ the multiplier given on `set pointsize`).
+
+ The defaults for the line and point types is the index. The defaults for
+ the width and size are both unity.
+
+ Linestyles created by this mechanism do not replace the default linetype
+ styles; both may be used. If you want plots to use the defined styles in
+ preference to the default linetypes, please see `set style increment`.
+
+ Not all terminals support the `linewidth` and `pointsize` features; if
+ not supported, the option will be ignored.
+
+ Terminal-independent colors may be assigned using either
+ `linecolor <colorspec>` or `linetype <colorspec>`, abbreviated `lc` or `lt`.
+ This requires giving a RGB color triple, a known palette color name,
+ a fractional index into the current palette, or a constant value from the
+ current mapping of the palette onto cbrange.
+ See `colors`, `colorspec`, `set palette`, `colornames`, `cbrange`.
+
+ `set style line <n> linetype <lt>` will set both a terminal-dependent dot/dash
+ pattern and color. The commands`set style line <n> linecolor <colorspec>` or
+ `set style line <n> linetype <colorspec>` will set a new line color while
+ leaving the existing dot-dash pattern unchanged.
+
+ In 3d mode (`splot` command), the special keyword `palette` is allowed as a
+ shorthand for "linetype palette z". The color value corresponds to the
+ z-value (elevation) of the splot, and varies smoothly along a line or surface.
+
+ Examples:
+ Suppose that the default lines for indices 1, 2, and 3 are red, green, and
+ blue, respectively, and the default point shapes for the same indices are a
+ square, a cross, and a triangle, respectively. Then
+
+ set style line 1 lt 2 lw 2 pt 3 ps 0.5
+
+ defines a new linestyle that is green and twice the default width and a new
+ pointstyle that is a half-sized triangle. The commands
+
+ set style function lines
+ plot f(x) lt 3, g(x) ls 1
+
+ will create a plot of f(x) using the default blue line and a plot of g(x)
+ using the user-defined wide green line. Similarly the commands
+
+ set style function linespoints
+ plot p(x) lt 1 pt 3, q(x) ls 1
+
+ will create a plot of p(x) using the default triangles connected by a red
+ line and q(x) using small triangles connected by a green line.
+
+ splot sin(sqrt(x*x+y*y))/sqrt(x*x+y*y) w l pal
+
+ creates a surface plot using smooth colors according to `palette`. Note,
+ that this works only on some terminals. See also `set palette`, `set pm3d`.
+
+ set style line 10 linetype 1 linecolor rgb "cyan"
+
+ will assign linestyle 10 to be a solid cyan line on any terminal that
+ supports rgb colors.
+
+4 plotting styles
+?plotting styles
+
+ The commands `set style data` and `set style function` change the
+ default plotting style for subsequent `plot` and `splot` commands.
+
+ The types used for all line and point styles (i.e., solid, dash-dot, color,
+ etc. for lines; circles, squares, crosses, etc. for points) will be either
+ those specified on the `plot` or `splot` command or will be chosen
+ sequentially from the types available to the terminal in use. Use the
+ command `test` to see what is available.
+
+ None of the styles requiring more than two columns of information
+ (e.g., `errorbars` or `errorlines`) can be used with `splot`s or
+ function `plot`s. Neither `boxes`, `filledcurves` nor any
+ of the `steps` styles can be used with `splot`s. If an inappropriate style
+ is specified, it will be changed to `points`.
+
+ The above caveat does not apply to `plot with labels`, for which the third
+ column specifies a data source rather than coordinate information.
+ See `set style labels`.
+
+ For 2-d data with more than two columns, `gnuplot` is picky about the
+ allowed `errorbars` and `errorlines` styles. The `using` option on the
+ `plot` command can be used to set up the correct columns for the style
+ you want. (In this discussion, "column" will be used to refer both to
+ a column in the data file and an entry in the `using` list.)
+
+ For three columns, only `xerrorbars`, `yerrorbars` (or `errorbars`),
+ `xerrorlines`, `yerrorlines` (or `errorlines`), `boxes`,
+ and `boxerrorbars` are allowed. If another plot style is used, the style
+ will be changed to `yerrorbars`. The `boxerrorbars` style will
+ calculate the boxwidth automatically.
+
+ For four columns, only `xerrorbars`, `yerrorbars` (or `errorbars`),
+ `xyerrorbars`, `xerrorlines`, `yerrorlines` (or `errorlines`), `xyerrorlines`,
+ `boxxyerrorbars`, and `boxerrorbars` are allowed. An illegal
+ style will be changed to `yerrorbars`.
+
+ Five-column data allow only the `boxerrorbars`, `financebars`, and
+ `candlesticks` styles. An illegal style will be changed to `boxerrorbars`
+ before plotting.
+
+ Six- and seven-column data only allow the `xyerrorbars`,
+ `xyerrorlines`, and `boxxyerrorbars` styles. Illegal styles will be
+ changed to `xyerrorbars` before plotting.
+
+ For more information about error bars with and without lines,
+ please see `plot errorlines` and `plot errorbars`.
+
+4 set style rectangle
+?commands set style rectangle
+?commands unset style rectangle
+?commands show style rectangle
+?set style rectangle
+?unset style rectangle
+?show style rectangle
+
+ Rectangles defined with the `set object rectangle` command can have individual
+ styles. However, if a rectangle is not assigned a private style then it
+ inherits a default that is taken from the `set style rectangle` command.
+
+ Syntax:
+ set style rectangle {front|back} {fillcolor <colorspec>} {fs <fillstyle>}
+ {lw|linewidth <lw>}
+
+ See `colorspec` and `fillstyle`. `fillcolor` may be abbreviated as `fc`.
+
+ Examples:
+ set style rectangle back fc rgb "white" fs solid 1.0 border -1
+ set style rectangle fc linsestyle 3 fs pattern 2 noborder
+
+ The default values correspond to solid fill with the background color and a
+ black border.
+
+5 boxerrorbars
+?commands set style boxerrorbars
+?set style boxerrorbars
+?plotting styles boxerrorbars
+?style boxerrorbars
+?boxerrorbars
+ The `boxerrorbars` style is only relevant to 2-d data plotting. It is a
+ combination of the `boxes` and `yerrorbars` styles. The boxwidth will come
+ from the fourth column if the y errors are in the form of "ydelta" and the
+ boxwidth was not previously set equal to -2.0 (`set boxwidth -2.0`) or from
+ the fifth column if the y errors are in the form of "ylow yhigh". The
+ special case `boxwidth = -2.0` is for four-column data with y errors in the
+ form "ylow yhigh". In this case the boxwidth will be calculated so that each
+ box touches the adjacent boxes. The width will also be calculated in cases
+ where three-column data are used.
+
+ The box height is determined from the y error in the same way as it is for
+ the `yerrorbars` style---either from y-ydelta to y+ydelta or from ylow to
+ yhigh, depending on how many data columns are provided.
+ See also
+^ <a href="http://www.gnuplot.info/demo/mgr.html">
+ errorbar demo.
+^ </a>
+5 boxes
+?commands set style boxes
+?set style boxes
+?plotting styles boxes
+?style boxes
+?boxes
+ The `boxes` style is only relevant to 2-d plotting. It draws a box centered
+ about the given x coordinate from the x axis (not the graph border) to the
+ given y coordinate. The width of the box is obtained in one of three ways.
+ If it is a data plot and the data file has a third column, this will be used
+ to set the width of the box. If not, if a width has been set using the `set
+ boxwidth` command, this will be used. If neither of these is available, the
+ width of each box will be calculated automatically so that it touches the
+ adjacent boxes.
+
+ The interior of the boxes is drawn according to the current fillstyle.
+ See `set style fill` for details. Alternatively a new fillstyle
+ may be specified in the plot command.
+
+ For fillstyle `empty` the box is filled with the background color.
+
+ For fillstyle `solid` the box is filled with a solid rectangle of the
+ current drawing color. There is an optional parameter <density> that
+ controls the fill density; it runs from 0 (background color) to 1
+ (current drawing color).
+
+ For fillstyle `pattern` the box is filled in the current drawing color with
+ a pattern, if supported by the terminal driver.
+
+ Examples:
+
+ To plot a data file with solid filled boxes with a small vertical space
+ separating them (bargraph):
+
+ set boxwidth 0.9 relative
+ set style fill solid 1.0
+ plot 'file.dat' with boxes
+
+ To plot a sine and a cosine curve in pattern-filled boxes style:
+
+ set style fill pattern
+ plot sin(x) with boxes, cos(x) with boxes
+
+ The sin plot will use pattern 0; the cos plot will use pattern 1.
+ Any additional plots would cycle through the patterns supported by the
+ terminal driver.
+
+ To specify explicit fillstyles for each dataset:
+
+ plot 'file1' with boxes fs solid 0.25, \
+ 'file2' with boxes fs solid 0.50, \
+ 'file3' with boxes fs solid 0.75, \
+ 'file4' with boxes fill pattern 1, \
+ 'file5' with boxes fill empty
+
+ Currently only the following terminal drivers support fillstyles other
+ than `empty`:
+ x11, windows, pm, wxt, postscript, fig, pbm, png, gif, hpdj, hppj, hpljii,
+ hp500c, jpeg, nec_cp6, epson_180dpi, epson_60dpi, epson_lx800, okidata, starc
+ and tandy_60dpi. The BeOS driver (`be`) is untested.
+5 boxxyerrorbars
+?commands set style boxxyerrorbars
+?set style boxxyerrorbars
+?plotting styles boxxyerrorbars
+?style boxxyerrorbars
+?boxxyerrorbars
+ The `boxxyerrorbars` style is only relevant to 2-d data plotting. It is a
+ combination of the `boxes` and `xyerrorbars` styles.
+
+ The box width and height are determined from the x and y errors in the same
+ way as they are for the `xyerrorbars` style---either from xlow to xhigh and
+ from ylow to yhigh, or from x-xdelta to x+xdelta and from y-ydelta to
+ y+ydelta , depending on how many data columns are provided.
+
+ If filled-box support is present, then the interior of the boxes is drawn
+ according to the current fillstyle. See `set style fill` and `boxes` for
+ details. Alternatively a new fillstyle may be specified in the plot command.
+5 candlesticks
+?commands set style candlesticks
+?set style candlesticks
+?plotting styles candlesticks
+?style candlesticks
+?candlesticks
+ The `candlesticks` style can be used for 2-d data plotting of financial
+ data or for generating box-and-whisker plots of statistical data.
+ Five columns of data are required; in order, these should be the x
+ coordinate (most likely a date) and the opening, low, high, and closing
+ prices. The symbol is a rectangular box, centered horizontally at the x
+ coordinate and limited vertically by the opening and closing prices. A
+ vertical line segment at the x coordinate extends up from the top of the
+ rectangle to the high price and another down to the low. The vertical line
+ will be unchanged if the low and high prices are interchanged.
+
+ The width of the rectangle can be controlled by the `set boxwidth` command.
+ For backwards compatibility with earlier gnuplot versions, when the
+ boxwidth parameter has not been set then the width of the candlestick
+ rectangle is controlled by `set bars <width>`.
+
+ By default the vertical line segments have no crossbars at the top and
+ bottom. If you want crossbars, which are typically used for box-and-whisker
+ plots, then add the keyword `whiskerbars` to the plot command. By default
+ these whiskerbars extend the full horizontal width of the candlestick, but
+ you can modify this by specifying a fraction of the full width.
+
+ By default the rectangle is empty if (open < close), and filled with three
+ vertical bars if (close < open). If filled-boxes support is present, then
+ the rectangle is colored according to `set style fill <fillstyle>`.
+ See `set bars` and `financebars`. See also
+^ <a href="http://gnuplot.sourceforge.net/demo/candlesticks.html">
+ finance demos
+^ </a>
+ .
+
+ Note: To place additional symbols, such as the median value, on a
+ box-and-whisker plot requires additional plot commands as in this example:
+
+ # Data columns: X Min 1stQuartile Median 3rdQuartile Max
+ set bars 4.0
+ set style fill empty
+ plot 'stat.dat' using 1:3:2:6:5 with candlesticks title 'Quartiles', \
+ '' using 1:4:4:4:4 with candlesticks lt -1 notitle
+
+ # Plot with crossbars on the whiskers, crossbars are 50% of full width
+ plot 'stat.dat' using 1:3:2:6:5 with candlesticks whiskerbars 0.5
+
+ See `set boxwidth`, `set bars` and `set style fill`.
+5 dots
+?commands set style dots
+?set style dots
+?plotting styles dots
+?style dots
+?dots
+ The `dots` style plots a tiny dot at each point; this is useful for scatter
+ plots with many points. For some terminals (post, pdf) the size of the dot can
+ be controlled by changing the linewidth.
+5 filledcurves
+?commands set style filledcurves
+?set style filledcurves
+?plotting styles filledcurves
+?style filledcurves
+?filledcurves
+ The `filledcurves` style is only relevant to 2-d plotting. Three variants
+ are possible. The first two variants require either a function or two columns
+ of input data, and may be further modified by the options listed below.
+ The first variant, `closed`, treats the curve itself as a closed polygon.
+ This is the default if there are two columns of input data.
+
+ The second variant is to fill the area between the curve and a given axis,
+ a horizontal or vertical line, or a point.
+
+ The third variant requires three columns of input data: the x coordinate and
+ two y coordinates corresponding to two curves sampled at the same set of
+ x coordinates; the area between the two curves is filled.
+ This is the default if there are three or more columns of input data.
+
+ Syntax:
+
+ set style [data | function] filledcurves [option]
+ plot ... with filledcurves [option]
+
+ where the option can be
+
+ [closed | {above | below} {x1 | x2 | y1 | y2}[=<a>] | xy=<x>,<y>]
+
+ The first two plot variants can be further modified by the options
+
+ filledcurves closed ... just filled closed curve,
+ filledcurves x1 ... x1 axis,
+ filledcurves x2 ... x2 axis, etc for y1 and y2 axes,
+ filledcurves y1=0 ... line y=0 (at y1 axis) ie parallel to x1 axis,
+ filledcurves y2=42 ... line y=42 (at y2 axis) ie parallel to x2, etc,
+ filledcurves xy=10,20 ... point 10,20 of x1,y1 axes (arc-like shape).
+
+ Example of filling the area between two input curves.
+^ <a href="http://www.gnuplot.info/demo/fillbetween.html">
+ fill between curves demo.
+^ </a>
+
+ plot 'data' using 1:2:3 with filledcurves
+
+ The `above` and `below` options apply both to commands of the form
+ ... filledcurves above {x1|x2|y1|y2}=<val>
+ and to commands of the form
+ ... using 1:2:3 with filledcurves below
+ In either case the option limits the filled area to one side of the bounding
+ line or curve.
+
+ Note: Not all terminal types support this plotting mode.
+
+ Zoom of a filled curve drawn from a datafile may produce empty or incorrect
+ area because gnuplot is clipping points and lines, and not areas.
+
+ If the values of <a>, <x>, <y> are out of the drawing boundary, then they
+ are moved to the graph boundary. Then the actually filled area in the case
+ of option xy=<x>,<y> will depend on xrange and yrange.
+5 financebars
+?commands set style financebars
+?set style financebars
+?plotting styles financebars
+?style financebars
+?financebars
+ The `financebars` style is only relevant for 2-d data plotting of financial
+ data. Five columns of data are required; in order, these should be the x
+ coordinate (most likely a date) and the opening, low, high, and closing
+ prices. The symbol is a vertical line segment, located horizontally at the x
+ coordinate and limited vertically by the high and low prices. A horizontal
+ tic on the left marks the opening price and one on the right marks the
+ closing price. The length of these tics may be changed by `set bars`. The
+ symbol will be unchanged if the high and low prices are interchanged.
+ See `set bars` and `candlesticks`, and also the
+^ <a href="http://www.gnuplot.info/demo/finance.html">
+ finance demo.
+^ </a>
+5 fsteps
+?commands set style fsteps
+?set style fsteps
+?plotting styles fsteps
+?style fsteps
+?fsteps
+ The `fsteps` style is only relevant to 2-d plotting. It connects consecutive
+ points with two line segments: the first from (x1,y1) to (x1,y2) and the
+ second from (x1,y2) to (x2,y2).
+ See also
+^ <a href="http://www.gnuplot.info/demo/steps.html">
+ steps demo.
+^ </a>
+5 histeps
+?commands set style histeps
+?set style histeps
+?plotting styles histeps
+?style histeps
+?histeps
+ The `histeps` style is only relevant to 2-d plotting. It is intended for
+ plotting histograms. Y-values are assumed to be centered at the x-values;
+ the point at x1 is represented as a horizontal line from ((x0+x1)/2,y1) to
+ ((x1+x2)/2,y1). The lines representing the end points are extended so that
+ the step is centered on at x. Adjacent points are connected by a vertical
+ line at their average x, that is, from ((x1+x2)/2,y1) to ((x1+x2)/2,y2).
+
+ If `autoscale` is in effect, it selects the xrange from the data rather than
+ the steps, so the end points will appear only half as wide as the others.
+ See also
+^ <a href="http://www.gnuplot.info/demo/steps.html">
+ steps demo.
+^ </a>
+
+ `histeps` is only a plotting style; `gnuplot` does not have the ability to
+ create bins and determine their population from some data set.
+5 histograms
+?commands set style histogram
+?set style histogram
+?style histograms
+?plotting styles histograms
+?histograms
+ The `histograms` style is only relevant to 2-d plotting. It produces a bar
+ chart from a sequence of data columns in parallel. Each element of the
+ `plot` command must specify a single input data source (e.g. one column of
+ the input file), possibly with associated tic values or key titles.
+ Four styles of histogram layout are currently supported.
+
+ set style histogram clustered {gap <gapsize>}
+ set style histogram errorbars {gap <gapsize>} {<linewidth>}
+ set style histogram rowstacked
+ set style histogram columnstacked
+
+ The default style corresponds to `set style histogram clustered gap 2`.
+ In this style, each set of parallel data values is collected into a group of
+ boxes clustered at the x-axis coordinate corresponding to their sequential
+ position (row #) in the selected datafile columns. Thus if <n> datacolumns are
+ selected, the first cluster is centered about x=1, and contains <n> boxes whose
+ heights are taken from the first entry in the corresponding <n> data columns.
+ This is followed by a gap and then a second cluster of boxes centered about x=2
+ corresponding to the second entry in the respective data columns, and so on.
+ The default gap width of 2 indicates that the empty space between clusters is
+ equivalent to the width of 2 boxes. All boxes derived from any one column
+ are given the same fill color and/or pattern (see `set style fill`).
+
+ Each cluster of boxes is derived from a single row of the input data file.
+ It is common in such input files that the first element of each row is a
+ label. Labels from this column may be placed along the x-axis underneath
+ the appropriate cluster of boxes with the `xticlabels` option to `using`.
+
+ The `errorbars` style is very similar to the `clustered` style, except that
+ it requires two columns of input for each entry. The first column is treated
+ as the height (y-value) of that box, exactly as for the `clustered` style.
+ The second column is treated as an error magnitude, and used to generate a
+ vertical error bar at the top of the box. The appearance of the error bar is
+ controlled by the current value of `set bars` and by the optional <linewidth>
+ specification.
+
+ Two styles of stacked histogram are supported, chosen by the command
+ `set style histogram {rowstacked|columnstacked}`. In these styles the data
+ values from the selected columns are collected into stacks of boxes.
+ Positive values stack upwards from y=0; negative values stack downwards.
+ Mixed positive and negative values will produce both an upward stack and a
+ downward stack. The default stacking mode is `rowstacked`.
+
+ The `rowstacked` style places a box resting on the x-axis for each
+ data value in the first selected column; the first data value results in
+ a box a x=1, the second at x=2, and so on. Boxes corresponding to the
+ second and subsequent data columns are layered on top of these, resulting
+ in a stack of boxes at x=1 representing the first data value from each
+ column, a stack of boxes at x=2 representing the second data value from
+ each column, and so on. All boxes derived from any one column are given the
+ same fill color and/or pattern (see `set style fill`).
+
+ The `columnstacked` style is similar, except that each stack of boxes is
+ built up from a single data column. Each data value from the first specified
+ column yields a box in the stack at x=1, each data value from the second
+ specified column yields a box in the stack at x=2, and so on. In this style
+ the color of each box is taken from the row number, rather than the column
+ number, of the corresponding data field.
+
+ Box widths may be modified using the `set boxwidth` command.
+ Box fill styles may be set using the `set style fill` command.
+
+ Histograms always use the x1 axis, but may use either y1 or y2.
+ If a plot contains both histograms and other plot styles, the non-histogram
+ plot elements may use either the x1 or the x2 axis.
+
+ Examples:
+
+ To plot a data file containing multiple columns of data as a histogram
+ of clustered boxes (the default style):
+
+ set boxwidth 0.9 relative
+ set style data histograms
+ set style fill solid 1.0 border -1
+ plot 'file.dat' using 2, '' using 4, '' using 6
+
+ This will produce a plot with clusters of three boxes (vertical bars) centered
+ at each integral value on the x axis. If the first column of the input file
+ contains labels, they may be placed along the x-axis using the variant command
+
+ plot 'file.dat' using 2, '' using 4, '' using 6:xticlabels(1)
+
+ If the file contains both a magnitude and an error estimate for each value,
+ then error bars can be added to the plot. The following commands will add
+ error bars extending from (y-<error>) to (y+<error>), capped by horizontal bar
+ ends drawn the same width as the box itself. The error bars and bar ends are
+ drawn with linewidth 2 using the border linetype from the current fill style.
+
+ set bars fullwidth
+ set style fill solid border -1
+ set style histogram errorbars gap 2 lw 2
+ plot 'file.dat' using 2:3, '' using 4:5, '' using 6:7:xticlabels(1)
+
+ To plot the same data as a rowstacked histogram:
+
+ set style histogram rows
+ plot 'file.dat' using 2, '' using 4, '' using 6:xtic(1)
+
+ This will produce a plot in which each vertical bar contains a stack of three
+ segments, corresponding in height to the values found in columns 2, 4 and 6
+ of the datafile.
+
+ Finally, the commands
+
+ set style histogram columnstacked
+ plot 'file.dat' using 2, '' using 4, '' using 6
+
+ will produce three vertical stacks. The stack at x=1 will contain a box for
+ each entry in column 2 of the datafile. The stack at x=2 will contain a box
+ for each parallel entry in column 4 of the datafile, and the stack at x=3 a
+ box for each entry of column 6. Because this interchanges gnuplot's usual
+ interpretation of input rows and columns, the specification of key titles and
+ x-axis tic labels must also be modified.
+
+ set style histogram columnstacked
+ plot '' u 5:key(1) # uses first column to generate key titles
+ plot '' u 5 title columnhead # uses first row to generate xtic labels
+6 newhistogram
+?newhistogram
+?histograms newhistogram
+ More than one set of histograms can appear in a single plot. In this case you
+ can force a gap between them, and a separate label for each set, by using the
+ plot command `newhistogram {"<title>"} {<linetype>} {at <x-coord>}`.
+ For example
+
+ set style histogram cluster
+ plot newhistogram "Set A", 'a' using 1, '' using 2, '' using 3, \
+ newhistogram "Set B", 'b' using 1, '' using 2, '' using 3
+
+ The labels "Set A" and "Set B" will appear beneath the respective sets of
+ histograms, under the overall x axis label.
+
+ The newhistogram command can also be used to force histogram coloring to
+ begin with a specific color (linetype). By default colors will continue to
+ increment successively even across histogram boundaries. Here is an example
+ using the same coloring for multiple histograms
+ plot newhistogram "Set A" lt 4, 'a' using 1, '' using 2, '' using 3, \
+ newhistogram "Set B" lt 4, 'b' using 1, '' using 2, '' using 3
+
+ The `at <x-coord>` option only applies to column-stacked histograms.
+5 image
+?commands set style image
+?set style image
+?plotting styles image
+?style image
+?image
+ The `image` style is intendend for plotting 2D images. It may be used for
+ both `plot` and `splot` in the form of 3D data (x,y,value) or projected 4D
+ data (x,y,z,value), respectively. It is assumed that in the viewing plane
+ the image data forms an equidistant sampling grid in the viewing plane along
+ two, not necessarily orthogonal, directions. In other words, groups of
+ four adjacent points are assumed to form the same size parallelogram. The
+ variable `value` in the tuples represent a palette color (gray value) for
+ indexing in the current palette.
+
+ The `image` style will attempt to create a properly positioned and scaled
+ data matrix to match the plot borders for those terminals supporting palettes
+ and images. Such output is efficient and draws quickly. However, when a
+ terminal driver does not support palettes and images, or when image support
+ is not implemented, the `image` style reverts to drawing filled rectangular
+ boxes for pixels, which is not as efficient. General parallelogram-shaped
+ images currently always have filled parallelograms for pixels.
+
+ The coordinate of each data point of an image will lie at the center of a
+ pixel. That is, an M x N set of data will form an image with M x N pixels.
+ This is slightly different than pm3d elements where an M x N set of data
+ will form a surface of (M-1) x (N-1) elements. The scan directions for the
+ image data grid can be any of eight possible combinations.
+
+ Here are some specific comments about particular terminal drivers:
+
+ x11 and wxt - Pixels are either repeated or decimated to fit the display
+ resolution; no other processing (filtering) is done. Thus, aliasing may
+ occur when decimating images having high spatial frequency content.
+
+ postscript (pslatex, epslatex, pstex) - Image is copied in its original
+ resolution, and sample interpolation is turned off.
+
+ See also `rgbimage`.
+5 impulses
+?commands set style impulses
+?set style impulses
+?plotting styles impulses
+?style impulses
+?impulses
+ The `impulses` style displays a vertical line from the x axis (not the graph
+ border), or from the grid base for `splot`, to each point.
+5 labels
+?commands set style labels
+?set style labels
+?plotting styles labels
+?style labels
+?labels
+ The `labels` style is available only if gnuplot is built with configuration
+ option --enable-datastrings. For a 2-D plot with labels you must specify
+ 3 input data columns; the text string found in the third column is printed at
+ the X and Y coordinates generated by the first two column specifiers. The
+ font, color, rotation angle and other properties of the printed text may be
+ specified as additional command options (see `set label`). The example below
+ will generate a 2-D plot with text labels taken from column 4 of the input
+ file (`tc lt 2` is shorthand for `textcolor linetype 2`, which is green).
+
+ plot 'datafile' using 1:(0.5 * $2):4 with labels font "arial,11" tc lt 2
+
+ The `labels` style can also be used in 3-D plots. In this case four input
+ column specifiers are required, corresponding to X Y Z and text.
+
+ splot 'datafile' using 1:2:3:4 with labels
+
+ See also `datastrings`, `set style data`.
+5 lines
+?commands set style lines
+?set style lines
+?plotting styles lines
+?style lines
+?lines
+ The `lines` style connects adjacent points with straight line segments.
+ See also `linetype`, `linewidth`, and `linestyle`.
+5 linespoints
+?commands set style linespoints
+?commands set style lp
+?set style linespoints
+?plotting styles linespoints
+?set style lp
+?style linespoints
+?style lp
+?linespoints
+?lp
+ The `linespoints` style does both `lines` and `points`, that is, it draws a
+ small symbol at each point and then connects adjacent points with straight
+ line segments. The command `set pointsize` may be used to change the size of
+ the points. See `set pointsize` for its usage.
+
+ `linespoints` may be abbreviated `lp`.
+5 points
+?commands set style points
+?set style points
+?plotting styles points
+?style points
+?points
+ The `points` style displays a small symbol at each point. The command `set
+ pointsize` may be used to change the size of the points. See `set pointsize`
+ for its usage.
+5 steps
+?commands set style steps
+?set style steps
+?plotting styles steps
+?style steps
+?steps
+ The `steps` style is only relevant to 2-d plotting. It connects consecutive
+ points with two line segments: the first from (x1,y1) to (x2,y1) and the
+ second from (x2,y1) to (x2,y2).
+ See also
+^ <a href="http://www.gnuplot.info/demo/steps.html">
+ steps demo.
+^ </a>
+5 rgbimage
+?commands set style rgbimage
+?set style rgbimage
+?plotting styles rgbimage
+?style rgbimage
+?rgbimage
+ The `rgbimage` style is intended for plotting 2D images and is similar
+ in concept to `image`. See `image` for details. The difference is
+ that 5D data (x,y,r,g,b) for `plot` and 6D data (x,y,z,r,g,b) for `splot`
+ describe the coordinates and color components of an image.
+
+ See also `image`.
+5 vectors
+?commands set style vectors
+?set style vectors
+?plotting styles vectors
+?style vectors
+?vectors
+ The 2D `vectors` style draws a vector from (x,y) to (x+xdelta,y+ydelta).
+ Thus it requires four columns of data. It also draws a small arrowhead at the
+ end of the vector.
+ The 3D `vectors` style is similar, but requires six columns of data.
+ splot with vectors is supported only for `set mapping cartesian`.
+ The keywords "with vectors" may be followed by arrow style specifications.
+ See `arrowstyle` for more details.
+
+ Example:
+ plot 'file.dat' using 1:2:3:4 with vectors head filled lt 2
+ splot 'file.dat' using 1:2:3:(1):(1):(1) with vectors filled head lw 2
+
+ `set clip one` and `set clip two` affect vectors drawn in 2D.
+ Please see `set clip` and `arrowstyle`.
+5 xerrorbars
+?commands set style xerrorbars
+?set style xerrorbars
+?plotting styles xerrorbars
+?style xerrorbars
+?xerrorbars
+ The `xerrorbars` style is only relevant to 2-d data plots. `xerrorbars` is
+ like `dots`, except that a horizontal error bar is also drawn. At each point
+ (x,y), a line is drawn from (xlow,y) to (xhigh,y) or from (x-xdelta,y) to
+ (x+xdelta,y), depending on how many data columns are provided. A tic mark
+ is placed at the ends of the error bar (unless `set bars` is used---see
+ `set bars` for details).
+5 xyerrorbars
+?commands set style xyerrorbars
+?set style xyerrorbars
+?plotting styles xyerrorbars
+?style xyerrorbars
+?xyerrorbars
+ The `xyerrorbars` style is only relevant to 2-d data plots. `xyerrorbars` is
+ like `dots`, except that horizontal and vertical error bars are also drawn.
+ At each point (x,y), lines are drawn from (x,y-ydelta) to (x,y+ydelta) and
+ from (x-xdelta,y) to (x+xdelta,y) or from (x,ylow) to (x,yhigh) and from
+ (xlow,y) to (xhigh,y), depending upon the number of data columns provided. A
+ tic mark is placed at the ends of the error bar (unless `set bars` is
+ used---see `set bars` for details).
+
+ If data are provided in an unsupported mixed form, the `using` filter on the
+ `plot` command should be used to set up the appropriate form. For example,
+ if the data are of the form (x,y,xdelta,ylow,yhigh), then you can use
+
+ plot 'data' using 1:2:($1-$3):($1+$3):4:5 with xyerrorbars
+5 yerrorbars
+?commands set style yerrorbars
+?commands set style errorbars
+?plotting styles yerrorbars
+?plotting styles errorbars
+?set style yerrorbars
+?set style errorbars
+?style yerrorbars
+?style errorbars
+?yerrorbars
+ The `yerrorbars` (or `errorbars`) style is only relevant to 2-d data plots.
+ `yerrorbars` is like `points`, except that a vertical error bar is also drawn.
+ At each point (x,y), a line is drawn from (x,y-ydelta) to (x,y+ydelta) or
+ from (x,ylow) to (x,yhigh), depending on how many data columns are provided.
+ A tic mark is placed at the ends of the error bar (unless `set bars` is
+ used---see `set bars` for details).
+ See also
+^ <a href="http://www.gnuplot.info/demo/mgr.html">
+ errorbar demo.
+^ </a>
+5 xerrorlines
+?commands set style xerrorlines
+?set style xerrorlines
+?plotting styles xerrorlines
+?style xerrorlines
+?xerrorlines
+ The `xerrorlines` style is only relevant to 2-d data plots.
+ `xerrorlines` is like `linespoints`, except that a horizontal error
+ line is also drawn. At each point (x,y), a line is drawn from (xlow,y)
+ to (xhigh,y) or from (x-xdelta,y) to (x+xdelta,y), depending on how
+ many data columns are provided. A tic mark is placed at the ends of
+ the error bar (unless `set bars` is used---see `set bars` for details).
+5 xyerrorlines
+?commands set style xyerrorlines
+?set style xyerrorlines
+?plotting styles xyerrorlines
+?style xyerrorlines
+?xyerrorlines
+ The `xyerrorlines` style is only relevant to 2-d data plots.
+ `xyerrorlines` is like `linespoints`, except that horizontal and
+ vertical error bars are also drawn. At each point (x,y), lines are
+ drawn from (x,y-ydelta) to (x,y+ydelta) and from (x-xdelta,y) to
+ (x+xdelta,y) or from (x,ylow) to (x,yhigh) and from (xlow,y) to
+ (xhigh,y), depending upon the number of data columns provided. A tic
+ mark is placed at the ends of the error bar (unless `set bars` is
+ used---see `set bars` for details).
+
+ If data are provided in an unsupported mixed form, the `using` filter on the
+ `plot` command should be used to set up the appropriate form. For example,
+ if the data are of the form (x,y,xdelta,ylow,yhigh), then you can use
+
+ plot 'data' using 1:2:($1-$3):($1+$3):4:5 with xyerrorlines
+5 yerrorlines
+?commands set style yerrorlines
+?commands set style errorlines
+?plotting styles yerrorlines
+?plotting styles errorlines
+?set style yerrorlines
+?set style errorlines
+?style yerrorlines
+?style errorlines
+?yerrorlines
+ The `yerrorlines` (or `errorlines`) style is only relevant to 2-d data
+ plots. `yerrorlines` is like `linespoints`, except that a vertical
+ error line is also drawn. At each point (x,y), a line is drawn from
+ (x,y-ydelta) to (x,y+ydelta) or from (x,ylow) to (x,yhigh), depending
+ on how many data columns are provided. A tic mark is placed at the
+ ends of the error bar (unless `set bars` is used---see `set bars` for
+ details).
+ See also
+^ <a href="http://www.gnuplot.info/demo/mgr.html">
+ errorbar demo.
+^ </a>
+3 surface
+?commands set surface
+?commands unset surface
+?commands show surface
+?set surface
+?unset surface
+?show surface
+?surface
+?nosurface
+ The command `set surface` controls the display of surfaces by `splot`.
+
+ Syntax:
+ set surface
+ unset surface
+ show surface
+
+ The surface is drawn with the style specified by `with`, or else the
+ appropriate style, data or function.
+
+ Whenever `unset surface` is issued, `splot` will not draw points or lines
+ corresponding to the function or data file points. Contours may still be
+ drawn on the surface, depending on the `set contour` option. `unset surface;
+ set contour base` is useful for displaying contours on the grid base. See
+ also `set contour`.
+3 table
+?commands set table
+?set table
+?table
+ When `table` mode is enabled, `plot` and `splot` commands print out a
+ multicolumn ASCII table of X Y {Z} R values rather than creating an actual
+ plot on the current terminal. The character R takes on one of three values:
+ "i" if the point is in the active range, "o" if it is out-of-range, or "u"
+ if it is undefined. The data format is determined by the format of the axis
+ labels (see `set format`), and the columns are separated by single spaces.
+ This can be useful if you want to generate contours and then save them for
+ further use, perhaps for plotting with `plot`; see `set contour` for example.
+ The same method can be used to save interpolated data
+ (see `set samples` and `set dgrid3d`).
+
+ Syntax:
+ set table {"outfile"}
+ plot <whatever>
+ unset table
+
+ Tabular output is written to the named file, if any, otherwise it is written
+ to the current value of `set output`. You must explicitly `unset table`
+ in order to go back to normal plotting on the current terminal.
+3 terminal
+?commands set terminal
+?commands show terminal
+?set terminal
+?set term
+?show terminal
+?show term
+?set terminal push
+?set term push
+?terminal push
+?term push
+?push
+?set terminal pop
+?set term pop
+?terminal pop
+?term pop
+?pop
+ `gnuplot` supports many different graphics devices. Use `set terminal` to
+ tell `gnuplot` what kind of output to generate. Use `set output` to redirect
+ that output to a file or device.
+
+ Syntax:
+ set terminal {<terminal-type> | push | pop}
+ show terminal
+
+ If <terminal-type> is omitted, `gnuplot` will list the available terminal
+ types. <terminal-type> may be abbreviated.
+
+ If both `set terminal` and `set output` are used together, it is safest to
+ give `set terminal` first, because some terminals set a flag which is needed
+ in some operating systems.
+
+ Several terminals have many additional options. For example, see `png`,
+ or `postscript`.
+ The options used by a previous invocation `set term <term> <options>` of a
+ given `<term>` are remembered, thus subsequent `set term <term>` does
+ not reset them. This helps in printing, for instance, when switching
+ among different terminals---previous options don't have to be repeated.
+
+ The command `set term push` remembers the current terminal including its
+ settings while `set term pop` restores it. This is equivalent to `save term`
+ and `load term`, but without accessing the filesystem. Therefore they can be
+ used to achieve platform independent restoring of the terminal after printing,
+ for instance. After gnuplot's startup, the default terminal or that from
+ `startup` file is pushed automatically. Therefore portable scripts can rely
+ that `set term pop` restores the default terminal on a given platform unless
+ another terminal has been pushed explicitly.
+
+ For a complete list of available terminal types, see `terminal`.
+3 termoption
+?commands set termoption
+?set termoption
+?termoption
+ The `set termoption` command allows you to change the behaviour of the
+ current terminal without requiring a new `set terminal` command. Only one
+ option can be changed per command, and only a small number of options can
+ be changed this way. Currently the only options accepted are
+
+ set termoption {no}enhanced
+ set termoption font "<fontname>{,<fontsize>}"
+
+3 tics
+?commands set tics
+?commands unset tics
+?commands show tics
+?set tics
+?unset tics
+?show tics
+?tics
+ Control of the major (labelled) tics on all axes at once is possible with the
+ `set tics` command.
+
+ Fine control of the major (labelled) tics on all axes at once is possible
+ with the `set tics` command. The tics may be turned off with the `unset tics`
+ command, and may be turned on (the default state) with `set tics`. Similar
+ commands (by preceding 'tics' by the axis name) control the major tics on a
+ single axis.
+
+ Syntax:
+ set tics {axis | border} {{no}mirror}
+ {in | out} {scale {default | <major> {,<minor>}}}
+ {{no}rotate {by <ang>}} {offset <offset> | nooffset}
+ { format "formatstring" } { font "name{,<size>}" }
+ { textcolor <colorspec> }
+ set tics {front | back}
+ unset tics
+ show tics
+
+ The options in the first set above can be applied individually to
+ any or all axes, i.e., x, y, z, x2, y2, and cb.
+
+ Set tics `front` or `back` applies to all axes at once, but only for 2D plots
+ (not splot). It controls whether the tics are placed behind or in front of
+ the plot elements, in the case that there is overlap.
+
+ `axis` or `border` tells `gnuplot` to put the tics (both the tics themselves
+ and the accompanying labels) along the axis or the border, respectively. If
+ the axis is very close to the border, the `axis` option will move the
+ tic labels to outside the border in case the border is printed (see
+ `set border`). The relevant margin settings will usually be sized badly by
+ the automatic layout algorithm in this case.
+
+ `mirror` tells `gnuplot` to put unlabelled tics at the same positions on the
+ opposite border. `nomirror` does what you think it does.
+
+ `in` and `out` change the tic marks to be drawn inwards or outwards.
+
+ With `scale`, the size of the tic marks can be adjusted. If <minor> is not
+ specified, it is 0.5*<major>. The default size 1.0 for major tics and 0.5
+ for minor tics is requested by `scale default`.
+
+ `rotate` asks `gnuplot` to rotate the text through 90 degrees, which will be
+ done if the terminal driver in use supports text rotation. `norotate`
+ cancels this. `rotate by <ang>` asks for rotation by <ang> degrees, supported
+ by some terminal types.
+
+ The defaults are `border mirror norotate` for tics on the x and y axes, and
+ `border nomirror norotate` for tics on the x2 and y2 axes. For the z axis,
+ the default is `nomirror`.
+
+ The <offset> is specified by either x,y or x,y,z, and may be preceded by
+ `first`, `second`, `graph`, `screen`, or `character` to select the
+ coordinate system. <offset> is the offset of the tics texts from their
+ default positions, while the default coordinate system is `character`.
+ See `coordinates` for details. `nooffset` switches off the offset.
+
+ `set tics` with no options restores to place tics inwards. Every other
+ options are retained.
+
+ See also `set xtics` for more control of major (labelled) tic marks and
+ `set mxtics` for control of minor tic marks. These commands provide control
+ at a axis by axis basis.
+3 ticslevel
+ See `set xyplane`.
+3 ticscale
+?commands set ticscale
+?commands show ticscale
+?set ticscale
+?show ticscale
+?ticscale
+ The `set ticscale` command is deprecated, use `set tics scale` instead.
+3 timestamp
+?commands set timestamp
+?commands unset timestamp
+?commands show timestamp
+?set timestamp
+?unset timestamp
+?show timestamp
+?timestamp
+?notimestamp
+ The command `set timestamp` places the time and date of the plot in the left
+ margin.
+
+ Syntax:
+ set timestamp {"<format>"} {top|bottom} {{no}rotate}
+ {offset <xoff>{,<yoff>}} {font "<fontspec>"}
+ unset timestamp
+ show timestamp
+
+ The format string allows you to choose the format used to write the date and
+ time. Its default value is what asctime() uses: "%a %b %d %H:%M:%S %Y"
+ (weekday, month name, day of the month, hours, minutes, seconds, four-digit
+ year). With `top` or `bottom` you can place the timestamp at the top or
+ bottom of the left margin (default: bottom). `rotate` lets you write the
+ timestamp vertically, if your terminal supports vertical text. The constants
+ <xoff> and <yoff> are offsets that let you adjust the position more finely.
+ <font> is used to specify the font with which the time is to be written.
+
+ The abbreviation `time` may be used in place of `timestamp`.
+
+ Example:
+ set timestamp "%d/%m/%y %H:%M" offset 80,-2 font "Helvetica"
+
+ See `set timefmt` for more information about time format strings.
+3 timefmt
+?commands set timefmt
+?commands show timefmt
+?set timefmt
+?show timefmt
+?timefmt
+ This command applies to timeseries where data are composed of dates/times.
+ It has no meaning unless the command `set xdata time` is given also.
+
+ Syntax:
+ set timefmt "<format string>"
+ show timefmt
+
+ The string argument tells `gnuplot` how to read timedata from the datafile.
+ The valid formats are:
+
+@start table - first is interactive cleartext form
+ Format Explanation
+ %d day of the month, 1--31
+ %m month of the year, 1--12
+ %y year, 0--99
+ %Y year, 4-digit
+ %j day of the year, 1--365
+ %H hour, 0--24
+ %M minute, 0--60
+ %s seconds since the Unix epoch (1970-01-01, 00:00 UTC)
+ %S second, 0--60
+ %b three-character abbreviation of the name of the month
+ %B name of the month
+#\begin{tabular}{|cl|} \hline
+#\multicolumn{2}{|c|}{Time Series timedata Format Specifiers}\\
+#\hline \hline
+#Format & Explanation \\ \hline
+#\verb@%d@ & day of the month, 1--31 \\
+#\verb@%m@ & month of the year, 1--12 \\
+#\verb@%y@ & year, 0--99 \\
+#\verb@%Y@ & year, 4-digit \\
+#\verb@%j@ & day of the year, 1--365 \\
+#\verb@%H@ & hour, 0--24 \\
+#\verb@%M@ & minute, 0--60 \\
+#\verb@%s@ & seconds since the Unix epoch (1970-01-01 00:00 UTC) \\
+#\verb@%S@ & second, 0--60 \\
+#\verb@%b@ & three-character abbreviation of the name of the month \\
+#\verb@%B@ & name of the month \\
+%c l .
+%Format@Explanation
+%_
+%%d@day of the month, 1--31
+%%m@month of the year, 1--12
+%%y@year, 0--99
+%%Y@year, 4-digit
+%%j@day of the year, 1--365
+%%H@hour, 0--24
+%%M@minute, 0--60
+%%s@seconds since the Unix epoch (1970-01-01 00:00 UTC)
+%%S@second, 0--60
+%%b@three-character abbreviation of the name of the month
+%%B@name of the month
+%_
+@end table
+ Any character is allowed in the string, but must match exactly. \t (tab) is
+ recognized. Backslash-octals (\nnn) are converted to char. If there is no
+ separating character between the time/date elements, then %d, %m, %y, %H, %M
+ and %S read two digits each, %Y reads four digits and %j reads three digits.
+ %b requires three characters, and %B requires as many as it needs.
+
+ Spaces are treated slightly differently. A space in the string stands for
+ zero or more whitespace characters in the file. That is, "%H %M" can be used
+ to read "1220" and "12 20" as well as "12 20".
+
+ Each set of non-blank characters in the timedata counts as one column in the
+ `using n:n` specification. Thus `11:11 25/12/76 21.0` consists of three
+ columns. To avoid confusion, `gnuplot` requires that you provide a complete
+ `using` specification if your file contains timedata.
+
+ Since `gnuplot` cannot read non-numerical text, if the date format includes
+ the day or month in words, the format string must exclude this text. But
+ it can still be printed with the "%a", "%A", "%b", or "%B" specifier:
+ see `set format` for more details about these and other options for printing
+ timedata. (`gnuplot` will determine the proper month and weekday from the
+ numerical values.)
+
+ See also `set xdata` and `Time/date` for more information.
+
+ Example:
+ set timefmt "%d/%m/%Y\t%H:%M"
+ tells `gnuplot` to read date and time separated by tab. (But look closely at
+ your data---what began as a tab may have been converted to spaces somewhere
+ along the line; the format string must match what is actually in the file.)
+ See also
+^ <a href="http://www.gnuplot.info/demo/timedat.html">
+ time data demo.
+^ </a>
+3 title
+?commands set title
+?commands show title
+?set title
+?show title
+?title
+ The `set title` command produces a plot title that is centered at the top of
+ the plot. `set title` is a special case of `set label`.
+
+ Syntax:
+ set title {"<title-text>"} {offset <offset>} {font "<font>{,<size>}"}
+ {{textcolor | tc} {<colorspec> | default}} {{no}enhanced}
+ show title
+
+ If <offset> is specified by either x,y or x,y,z the title is moved by the
+ given offset. It may be preceded by `first`, `second`, `graph`, `screen`,
+ or `character` to select the coordinate system. See `coordinates` for
+ details. By default, the `character` coordinate system is used. For
+ example, "`set title offset 0,-1`" will change only the y offset of the
+ title, moving the title down by roughly the height of one character. The
+ size of a character depends on both the font and the terminal.
+
+ <font> is used to specify the font with which the title is to be written;
+ the units of the font <size> depend upon which terminal is used.
+
+ `textcolor <colorspec>` changes the color of the text. <colorspec> can be a
+ linetype, an rgb color, or a palette mapping. See help for `colorspec` and
+ `palette`.
+
+ `noenhanced` requests that the title not be processed by the enhanced text
+ mode parser, even if enhanced text mode is currently active.
+
+ `set title` with no parameters clears the title.
+
+ See `syntax` for details about the processing of backslash sequences and
+ the distinction between single- and double-quotes.
+3 tmargin
+?commands set tmargin
+?set tmargin
+?tmargin
+ The command `set tmargin` sets the size of the top margin.
+ Please see `set margin` for details.
+3 trange
+?commands set trange
+?commands show trange
+?set trange
+?show trange
+?trange
+ The `set trange` command sets the parametric range used to compute x and y
+ values when in parametric or polar modes. Please see `set xrange` for
+ details.
+3 urange
+?commands set urange
+?commands show urange
+?set urange
+?show urange
+?urange
+ The `set urange` and `set vrange` commands set the parametric ranges used
+ to compute x, y, and z values when in `splot` parametric mode.
+ Please see `set xrange` for details.
+3 variables
+?commands show variables
+?show variables
+ The `show variables` command lists all user-defined variables and their
+ values.
+
+ Syntax:
+ show variables {all}
+
+ With the optional keyword "all", also the `gnuplot-defined variables` that
+ begin with `GPVAL_` are listed.
+
+3 version
+?show version
+ The `show version` command lists the version of gnuplot being run, its last
+ modification date, the copyright holders, and email addresses for the FAQ,
+ the gnuplot-info mailing list, and reporting bugs--in short, the information
+ listed on the screen when the program is invoked interactively.
+
+ Syntax:
+ show version {long}
+
+ When the `long` option is given, it also lists the operating system, the
+ compilation options used when `gnuplot` was installed, the location of the
+ help file, and (again) the useful email addresses.
+3 view
+?commands set view
+?commands show view
+?set view
+?set view map
+?set view {no}equal {xy|xyz}
+?show view
+?view
+ The `set view` command sets the viewing angle for `splot`s. It controls how
+ the 3-d coordinates of the plot are mapped into the 2-d screen space. It
+ provides controls for both rotation and scaling of the plotted data, but
+ supports orthographic projections only. It supports both 3D projection or
+ orthogonal 2D projection into a 2D plot-like map.
+
+ Syntax:
+ set view <rot_x>{,{<rot_z>}{,{<scale>}{,<scale_z>}}}
+ set view map
+ set view {no}equal_axes
+ show view
+
+ where <rot_x> and <rot_z> control the rotation angles (in degrees) in a
+ virtual 3-d coordinate system aligned with the screen such that initially
+ (that is, before the rotations are performed) the screen horizontal axis is
+ x, screen vertical axis is y, and the axis perpendicular to the screen is z.
+ The first rotation applied is <rot_x> around the x axis. The second rotation
+ applied is <rot_z> around the new z axis.
+
+ Command `set view map` is used to represent the drawing as a map. It can be
+ used for `contour` plots, or for color `pm3d` maps. In the latter, take care
+ that you properly use `zrange` and `cbrange` for input data point filtering
+ and color range scaling, respectively.
+
+ <rot_x> is bounded to the [0:180] range with a default of 60 degrees, while
+ <rot_z> is bounded to the [0:360] range with a default of 30 degrees.
+ <scale> controls the scaling of the entire `splot`, while <scale_z> scales
+ the z axis only. Both scales default to 1.0.
+
+ Examples:
+ set view 60, 30, 1, 1
+ set view ,,0.5
+
+ The first sets all the four default values. The second changes only scale,
+ to 0.5.
+
+ The command `set view equal xy` forces the unit length of the x and y axes
+ to be on the same scale, and chooses that scale so that the plot will fit on
+ the page. The command `set view equal xyz` additionally sets the z axis
+ scale to match the x and y axes; however there is no guarantee that the
+ current z axis range will fit within the plot boundary.
+ By default all three axes are scaled independently to fill the available area.
+
+ See also `set ticslevel`.
+3 vrange
+?commands set vrange
+?commands show vrange
+?set vrange
+?show vrange
+?vrange
+ The `set urange` and `set vrange` commands set the parametric ranges used
+ to compute x, y, and z values when in `splot` parametric mode.
+ Please see `set xrange` for details.
+3 x2data
+?commands set x2data
+?commands show x2data
+?set x2data
+?show x2data
+?x2data
+ The `set x2data` command sets data on the x2 (top) axis to timeseries
+ (dates/times). Please see `set xdata`.
+3 x2dtics
+?commands set x2dtics
+?commands unset x2dtics
+?commands show x2dtics
+?set x2dtics
+?unset x2dtics
+?show x2dtics
+?x2dtics
+?nox2dtics
+ The `set x2dtics` command changes tics on the x2 (top) axis to days of the
+ week. Please see `set xdtics` for details.
+3 x2label
+?commands set x2label
+?commands show x2label
+?set x2label
+?show x2label
+?x2label
+ The `set x2label` command sets the label for the x2 (top) axis.
+ Please see `set xlabel`.
+3 x2mtics
+?commands set x2mtics
+?commands unset x2mtics
+?commands show x2mtics
+?set x2mtics
+?unset x2mtics
+?show x2mtics
+?x2mtics
+?nox2mtics
+ The `set x2mtics` command changes tics on the x2 (top) axis to months of the
+ year. Please see `set xmtics` for details.
+3 x2range
+?commands set x2range
+?commands show x2range
+?set x2range
+?show x2range
+?x2range
+ The `set x2range` command sets the horizontal range that will be displayed on
+ the x2 (top) axis. Please see `set xrange` for details.
+3 x2tics
+?commands set x2tics
+?commands unset x2tics
+?commands show x2tics
+?set x2tics
+?unset x2tics
+?show x2tics
+?x2tics
+?nox2tics
+ The `set x2tics` command controls major (labelled) tics on the x2 (top) axis.
+ Please see `set xtics` for details.
+3 x2zeroaxis
+?commands set x2zeroaxis
+?commands unset x2zeroaxis
+?commands show x2zeroaxis
+?set x2zeroaxis
+?unset x2zeroaxis
+?show x2zeroaxis
+?x2zeroaxis
+?nox2zeroaxis
+ The `set x2zeroaxis` command draws a line at the origin of the x2 (top) axis
+ (y2 = 0). For details, please see `set zeroaxis`.
+3 xdata
+?commands set xdata
+?commands show xdata
+?set xdata
+?show xdata
+?xdata
+ This command sets the datatype on the x axis to time/date. A similar command
+ does the same thing for each of the other axes.
+
+ Syntax:
+ set xdata {time}
+ show xdata
+
+ The same syntax applies to `ydata`, `zdata`, `x2data`, `y2data` and `cbdata`.
+
+ The `time` option signals that the datatype is indeed time/date. If the
+ option is not specified, the datatype reverts to normal.
+
+ See `set timefmt` to tell gnuplot how to read date or time data. The
+ time/date is converted to seconds from start of the century. There is
+ currently only one timefmt, which implies that all the time/date columns must
+ conform to this format. Specification of ranges should be supplied as quoted
+ strings according to this format to avoid interpretation of the time/date as
+ an expression.
+
+ The function 'strftime' (type "man strftime" on unix to look it up) is used
+ to print tic-mark labels. `gnuplot` tries to figure out a reasonable format
+ for this unless the `set format x "string"` has supplied something that does
+ not look like a decimal format (more than one '%' or neither %f nor %g).
+
+ See also `Time/date` for more information.
+3 xdtics
+?commands set xdtics
+?commands unset xdtics
+?commands show xdtics
+?set xdtics
+?unset xdtics
+?show xdtics
+?xdtics
+?noxdtics
+ The `set xdtics` commands converts the x-axis tic marks to days of the week
+ where 0=Sun and 6=Sat. Overflows are converted modulo 7 to dates. `set
+ noxdtics` returns the labels to their default values. Similar commands do
+ the same things for the other axes.
+
+ Syntax:
+ set xdtics
+ unset xdtics
+ show xdtics
+
+ The same syntax applies to `ydtics`, `zdtics`, `x2dtics`, `y2dtics` and
+ `cbdtics`.
+
+ See also the `set format` command.
+3 xlabel
+?commands set xlabel
+?commands show xlabel
+?set xlabel
+?show xlabel
+?xlabel
+ The `set xlabel` command sets the x axis label. Similar commands set labels
+ on the other axes.
+
+ Syntax:
+ set xlabel {"<label>"} {offset <offset>} {font "<font>{,<size>}"}
+ {{textcolor | tc} {lt <line_type> | default}} {{no}enhanced}
+ {rotate by <degrees>}
+ show xlabel
+
+ The same syntax applies to `x2label`, `ylabel`, `y2label`, `zlabel` and
+ `cblabel`.
+
+ If <offset> is specified by either x,y or x,y,z the label is moved by the
+ given offset. It may be preceded by `first`, `second`, `graph`, `screen`,
+ or `character` to select the coordinate system. See `coordinates` for
+ details. By default, the `character` coordinate system is used. For
+ example, "`set xlabel offset -1,0`" will change only the x offset of the
+ title, moving the label roughly one character width to the left. The size
+ of a character depends on both the font and the terminal.
+
+ <font> is used to specify the font in which the label is written; the units
+ of the font <size> depend upon which terminal is used.
+
+ `textcolor lt <n>` sets the text color to that of line type <n>.
+
+ `noenhanced` requests that the label text not be processed by the enhanced text
+ mode parser, even if enhanced text mode is currently active.
+
+ To clear a label, put no options on the command line, e.g., "`set y2label`".
+
+ The default positions of the axis labels are as follows:
+
+ xlabel: The x-axis label is centered below the bottom axis.
+
+ ylabel: The position of the y-axis label depends on the terminal, and can be
+ one of the following three positions:
+
+ 1. Horizontal text flushed left at the top left of the plot. Terminals that
+ cannot rotate text will probably use this method. If `set x2tics` is also
+ in use, the ylabel may overwrite the left-most x2tic label. This may be
+ remedied by adjusting the ylabel position or the left margin.
+
+ 2. Vertical text centered vertically at the left of the plot. Terminals
+ that can rotate text will probably use this method.
+
+ 3. Horizontal text centered vertically at the left of the plot. The EEPIC,
+ LaTeX and TPIC drivers use this method. The EEPIC driver will produce a
+ stack of characters so as not to overwrite the plot. With other drivers
+ (such as LaTeX and TPIC), the user probably has to insert line breaks
+ using \\ to prevent the ylabel from overwriting the plot.
+
+ zlabel: The z-axis label is centered along the z axis and placed in the space
+ above the grid level.
+
+ cblabel: The color box axis label is centered along the box and placed below
+ or right according to horizontal or vertical color box gradient.
+
+ y2label: The y2-axis label is placed to the right of the y2 axis. The
+ position is terminal-dependent in the same manner as is the y-axis label.
+
+ x2label: The x2-axis label is placed above the top axis but below the plot
+ title. It is also possible to create an x2-axis label by using new-line
+ characters to make a multi-line plot title, e.g.,
+
+ set title "This is the title\n\nThis is the x2label"
+
+ Note that double quotes must be used. The same font will be used for both
+ lines, of course.
+
+ The y and y2 axis labels can be explicitly rotated from their default
+ orientation, but this applies only to 2D plots and only on terminals
+ that support text rotation.
+
+ If you are not satisfied with the default position of an axis label, use `set
+ label` instead--that command gives you much more control over where text is
+ placed.
+
+ Please see `syntax` for further information about backslash processing
+ and the difference between single- and double-quoted strings.
+3 xmtics
+?commands set xmtics
+?commands unset xmtics
+?commands show xmtics
+?set xmtics
+?unset xmtics
+?show xmtics
+?xmtics
+?noxmtics
+ The `set xmtics` command converts the x-axis tic marks to months of the
+ year where 1=Jan and 12=Dec. Overflows are converted modulo 12 to months.
+ The tics are returned to their default labels by `unset xmtics`. Similar
+ commands perform the same duties for the other axes.
+
+ Syntax:
+ set xmtics
+ unset xmtics
+ show xmtics
+
+ The same syntax applies to `x2mtics`, `ymtics`, `y2mtics`, `zmtics` and
+ `cbmtics`.
+
+ See also the `set format` command.
+3 xrange
+?commands set xrange
+?commands show xrange
+?set xrange
+?show xrange
+?writeback
+?restore
+?xrange
+ The `set xrange` command sets the horizontal range that will be displayed.
+ A similar command exists for each of the other axes, as well as for the
+ polar radius r and the parametric variables t, u, and v.
+
+ Syntax:
+ set xrange { [{{<min>}:{<max>}}] {{no}reverse} {{no}writeback} }
+ | restore
+ show xrange
+
+ where <min> and <max> terms are constants, expressions or an asterisk to set
+ autoscaling. If the data are time/date, you must give the range as a quoted
+ string according to the `set timefmt` format. Any value omitted will not be
+ changed.
+
+ The same syntax applies to `yrange`, `zrange`, `x2range`, `y2range`, `cbrange`,
+ `rrange`, `trange`, `urange` and `vrange`.
+
+ The `reverse` option reverses the direction of the axis, e.g., `set xrange
+ [0:1] reverse` will produce an axis with 1 on the left and 0 on the right.
+ This is identical to the axis produced by `set xrange [1:0]`, of course.
+ `reverse` is intended primarily for use with `autoscale`.
+
+ The `writeback` option essentially saves the range found by `autoscale` in
+ the buffers that would be filled by `set xrange`. This is useful if you wish
+ to plot several functions together but have the range determined by only
+ some of them. The `writeback` operation is performed during the `plot`
+ execution, so it must be specified before that command. To restore,
+ the last saved horizontal range use `set xrange restore`. For example,
+
+ set xrange [-10:10]
+ set yrange [] writeback
+ plot sin(x)
+ set yrange restore
+ replot x/2
+
+ results in a yrange of [-1:1] as found only from the range of sin(x); the
+ [-5:5] range of x/2 is ignored. Executing `show yrange` after each command
+ in the above example should help you understand what is going on.
+
+ In 2-d, `xrange` and `yrange` determine the extent of the axes, `trange`
+ determines the range of the parametric variable in parametric mode or the
+ range of the angle in polar mode. Similarly in parametric 3-d, `xrange`,
+ `yrange`, and `zrange` govern the axes and `urange` and `vrange` govern the
+ parametric variables.
+
+ In polar mode, `rrange` determines the radial range plotted. <rmin> acts as
+ an additive constant to the radius, whereas <rmax> acts as a clip to the
+ radius---no point with radius greater than <rmax> will be plotted. `xrange`
+ and `yrange` are affected---the ranges can be set as if the graph was of
+ r(t)-rmin, with rmin added to all the labels.
+
+ Any range may be partially or totally autoscaled, although it may not make
+ sense to autoscale a parametric variable unless it is plotted with data.
+
+ Ranges may also be specified on the `plot` command line. A range given on
+ the plot line will be used for that single `plot` command; a range given by
+ a `set` command will be used for all subsequent plots that do not specify
+ their own ranges. The same holds true for `splot`.
+
+ Examples:
+
+ To set the xrange to the default:
+ set xrange [-10:10]
+
+ To set the yrange to increase downwards:
+ set yrange [10:-10]
+
+ To change zmax to 10 without affecting zmin (which may still be autoscaled):
+ set zrange [:10]
+
+ To autoscale xmin while leaving xmax unchanged:
+ set xrange [*:]
+3 xtics
+?commands set xtics
+?commands unset xtics
+?commands show xtics
+?set xtics
+?unset xtics
+?show xtics
+?xtics
+?noxtics
+ Fine control of the major (labelled) tics on the x axis is possible with the
+ `set xtics` command. The tics may be turned off with the `unset xtics`
+ command, and may be turned on (the default state) with `set xtics`. Similar
+ commands control the major tics on the y, z, x2 and y2 axes.
+
+ Syntax:
+ set xtics {axis | border} {{no}mirror}
+ {in | out} {scale {default | <major> {,<minor>}}}
+ {{no}rotate {by <ang>}} {offset <offset> | nooffset}
+ {add}
+ { autofreq
+ | <incr>
+ | <start>, <incr> {,<end>}
+ | ({"<label>"} <pos> {<level>} {,{"<label>"}...) }
+ { format "formatstring" } { font "name{,<size>}" }
+ { rangelimited }
+ { textcolor <colorspec> }
+ unset xtics
+ show xtics
+
+ The same syntax applies to `ytics`, `ztics`, `x2tics`, `y2tics` and `cbtics`.
+
+ `axis` or `border` tells `gnuplot` to put the tics (both the tics themselves
+ and the accompanying labels) along the axis or the border, respectively. If
+ the axis is very close to the border, the `axis` option will move the
+ tic labels to outside the border. The relevant margin settings will usually
+ be sized badly by the automatic layout algorithm in this case.
+
+ `mirror` tells `gnuplot` to put unlabelled tics at the same positions on the
+ opposite border. `nomirror` does what you think it does.
+
+ `in` and `out` change the tic marks to be drawn inwards or outwards.
+
+ With `scale`, the size of the tic marks can be adjusted. If <minor> is not
+ specified, it is 0.5*<major>. The default size 1.0 for major tics and 0.5
+ for minor tics is requested by `scale default`.
+
+ `rotate` asks `gnuplot` to rotate the text through 90 degrees, which will be
+ done if the terminal driver in use supports text rotation. `norotate`
+ cancels this. `rotate by <ang>` asks for rotation by <ang> degrees, supported
+ by some terminal types.
+
+ The defaults are `border mirror norotate` for tics on the x and y axes, and
+ `border nomirror norotate` for tics on the x2 and y2 axes. For the z axis,
+ the `{axis | border}` option is not available and the default is
+ `nomirror`. If you do want to mirror the z-axis tics, you might want to
+ create a bit more room for them with `set border`.
+
+ The <offset> is specified by either x,y or x,y,z, and may be preceded by
+ `first`, `second`, `graph`, `screen`, or `character` to select the
+ coordinate system. <offset> is the offset of the tics texts from their
+ default positions, while the default coordinate system is `character`.
+ See `coordinates` for details. `nooffset` switches off the offset.
+
+ Example:
+
+ Move xtics more closely to the plot.
+ set xtics offset 0,graph 0.05
+
+ `set xtics` with no options restores the default border or axis if xtics are
+ being displayed; otherwise it has no effect. Any previously specified tic
+ frequency or position {and labels} are retained.
+
+ Positions of the tics are calculated automatically by default or if the
+ `autofreq` option is given; otherwise they may be specified in either of
+ two forms:
+
+ The implicit <start>, <incr>, <end> form specifies that a series of tics will
+ be plotted on the axis between the values <start> and <end> with an increment
+ of <incr>. If <end> is not given, it is assumed to be infinity. The
+ increment may be negative. If neither <start> nor <end> is given, <start> is
+ assumed to be negative infinity, <end> is assumed to be positive infinity,
+ and the tics will be drawn at integral multiples of <incr>. If the axis is
+ logarithmic, the increment will be used as a multiplicative factor.
+
+ If you specify to a negative <start> or <incr> after a numerical value
+ (e.g., `rotate by <angle>` or `offset <offset>`), the parser fails because
+ it subtracts <start> or <incr> from that value. As a workaround, specify
+ `0-<start>` resp. `0-<incr>` in that case.
+
+ Example:
+ set xtics border offset 0,0.5 -5,1,5
+ Fails with 'invalid expression' at the last comma.
+ set xtics border offset 0,0.5 0-5,1,5
+ or
+ set xtics offset 0,0.5 border -5,1,5
+ Sets tics at the border, tics text with an offset of 0,0.5 characters, and
+ sets the start, increment, and end to -5, 1, and 5, as requested.
+
+ The `set grid` options 'front', 'back' and 'layerdefault' affect the drawing
+ order of the xtics, too.
+
+ Examples:
+
+ Make tics at 0, 0.5, 1, 1.5, ..., 9.5, 10.
+ set xtics 0,.5,10
+
+ Make tics at ..., -10, -5, 0, 5, 10, ...
+ set xtics 5
+
+ Make tics at 1, 100, 1e4, 1e6, 1e8.
+ set logscale x; set xtics 1,100,1e8
+
+ The explicit ("<label>" <pos> <level>, ...) form allows arbitrary tic
+ positions or non-numeric tic labels. In this form, the tics do not
+ need to be listed in numerical order. Each tic has a
+ position, optionally with a label. Note that the label is
+ a string enclosed by quotes. It may be a constant string, such as
+ "hello", may contain formatting information for converting the
+ position into its label, such as "%3f clients", or may be empty, "".
+ See `set format` for more information. If no string is given, the
+ default label (numerical) is used.
+
+ An explicit tic mark has a third parameter, the "level". The default
+ is level 0, a major tic. A level of 1 generates a minor tic. If the
+ level is specified, then the label must also be supplied.
+
+ Examples:
+ set xtics ("low" 0, "medium" 50, "high" 100)
+ set xtics (1,2,4,8,16,32,64,128,256,512,1024)
+ set ytics ("bottom" 0, "" 10, "top" 20)
+ set ytics ("bottom" 0, "" 10 1, "top" 20)
+
+ In the second example, all tics are labelled. In the third, only the end
+ tics are labelled. In the fourth, the unlabeled tic is a minor tic.
+
+ Normally if explicit tics are given, they are used instead of auto-generated
+ tics. Conversely if you specify `set xtics auto` or the like it will erase
+ any previously specified explicit tics. You can mix explicit and auto-
+ generated tics by using the keyword `add`, which must appear before
+ the tic style being added.
+
+ Example:
+ set xtics 0,.5,10
+ set xtics add ("Pi" 3.14159)
+
+ This will automatically generate tic marks every 0.5 along x, but will
+ also add an explicit labeled tic mark at pi.
+
+ However they are specified, tics will only be plotted when in range.
+
+ Format (or omission) of the tic labels is controlled by `set format`, unless
+ the explicit text of a label is included in the `set xtics ("<label>")` form.
+
+ Minor (unlabelled) tics can be added automatically by the `set mxtics`
+ command, or at explicit positions by the `set xtics ("" <pos> 1, ...)` form.
+4 xtics time_data
+?set xtics time_axis tics
+?xtics time_axis tics
+?time_axis tics
+ In case of timeseries data, axis tic position values must be given as quoted
+ dates or times according to the format `timefmt`. If the <start>, <incr>, <end>
+ form is used, <start> and <end> must be given according to `timefmt`, but
+ <incr> must be in seconds. Times will be written out according to the format
+ given on `set format`, however.
+
+ Examples:
+ set xdata time
+ set timefmt "%d/%m"
+ set xtics format "%b %d"
+ set xrange ["01/12":"06/12"]
+ set xtics "01/12", 172800, "05/12"
+
+ set xdata time
+ set timefmt "%d/%m"
+ set xtics format "%b %d"
+ set xrange ["01/12":"06/12"]
+ set xtics ("01/12", "" "03/12", "05/12")
+ Both of these will produce tics "Dec 1", "Dec 3", and "Dec 5", but in the
+ second example the tic at "Dec 3" will be unlabelled.
+4 xtics rangelimited
+?set xtics rangelimited
+?xtics rangelimited
+?rangelimited
+?range-frame
+ This option limits both the auto-generated axis tic labels and the
+ corresponding plot border to the range of values actually present in the data
+ that has been plotted. Note that this is independent of the current range
+ limits for the plot. For example, suppose that the data in "file.dat" all lies
+ in the range 2 < y < 4. Then the following commands will create a plot for
+ which the left-hand plot border (y axis) is drawn for only this portion of the
+ total y range, and only the axis tics in this region are generated.
+ I.e., the plot will be scaled to the full range on y, but there will be a gap
+ between 0 and 2 on the left border and another gap between 4 and 10. This
+ style is sometimes refered to as a `range-frame` graph.
+ set border 3
+ set yrange [0:10]
+ set ytics nomirror rangelimited
+ plot "file.dat"
+3 xyplane
+?commands set ticslevel
+?commands show ticslevel
+?set ticslevel
+?show ticslevel
+?ticslevel
+?commands set xyplane
+?commands show xyplane
+?set xyplane
+?show xyplane
+?xyplane
+ The `set xyplane` command adjusts the position at which the xy plane is drawn
+ in a 3D plot. The synonym "set ticslevel" is accepted for backwards
+ compatibility.
+
+ Syntax:
+ set ticslevel <frac>
+ set xyplane <frac>
+ set xyplane at <zvalue>
+ show xyplane
+
+ The form `set ticslevel <frac>` places the xy plane below the range in Z, where
+ the distance from the xy plane to Zmin is given as a fraction of the total
+ range in z. The default value is 0.5. Negative values are permitted, but tic
+ labels on the three axes may overlap.
+
+ To place the xy-plane at a position 'pos' on the z-axis, `ticslevel` may
+ be set equal to (pos - zmin) / (zmin - zmax). However, this position will
+ change if the z range is changed.
+
+ The alternative form `set xyplane at <zvalue>` fixes the placement of the
+ xy plane at a specific Z value regardless of the current z range. Thus to
+ force the x, y, and z axes to meet at a common origin one would specify
+ `set xyplane at 0`.
+
+ See also `set view`, and `set zeroaxis`.
+3 xzeroaxis
+?commands set xzeroaxis
+?commands unset xzeroaxis
+?commands show xzeroaxis
+?set xzeroaxis
+?unset xzeroaxis
+?show xzeroaxis
+?xzeroaxis
+?noxzeroaxis
+ The `set xzeroaxis` command draws a line at y = 0. For details,
+ please see `set zeroaxis`.
+3 y2data
+?commands set y2data
+?commands show y2data
+?set y2data
+?show y2data
+?y2data
+ The `set y2data` command sets y2 (right-hand) axis data to timeseries
+ (dates/times). Please see `set xdata`.
+3 y2dtics
+?commands set y2dtics
+?commands unset y2dtics
+?set y2dtics
+?unset y2dtics
+?show y2dtics
+?y2dtics
+?noy2dtics
+ The `set y2dtics` command changes tics on the y2 (right-hand) axis to days of
+ the week. Please see `set xdtics` for details.
+3 y2label
+?commands set y2label
+?commands show y2label
+?set y2label
+?show y2label
+?y2label
+ The `set y2label` command sets the label for the y2 (right-hand) axis.
+ Please see `set xlabel`.
+3 y2mtics
+?commands set y2mtics
+?commands unset y2mtics
+?commands show y2mtics
+?set y2mtics
+?unset y2mtics
+?show y2mtics
+?y2mtics
+?noy2mtics
+ The `set y2mtics` command changes tics on the y2 (right-hand) axis to months
+ of the year. Please see `set xmtics` for details.
+3 y2range
+?commands set y2range
+?commands show y2range
+?set y2range
+?show y2range
+?y2range
+ The `set y2range` command sets the vertical range that will be displayed on
+ the y2 (right-hand) axis. Please see `set xrange` for details.
+3 y2tics
+?commands set y2tics
+?commands unset y2tics
+?commands show y2tics
+?set y2tics
+?unset y2tics
+?show y2tics
+?y2tics
+?noy2tics
+ The `set y2tics` command controls major (labelled) tics on the y2 (right-hand)
+ axis. Please see `set xtics` for details.
+3 y2zeroaxis
+?commands set y2zeroaxis
+?commands unset y2zeroaxis
+?commands show y2zeroaxis
+?set y2zeroaxis
+?unset y2zeroaxis
+?show y2zeroaxis
+?y2zeroaxis
+?noy2zeroaxis
+ The `set y2zeroaxis` command draws a line at the origin of the y2 (right-hand)
+ axis (x2 = 0). For details, please see `set zeroaxis`.
+3 ydata
+?commands set ydata
+?commands show ydata
+?set ydata
+?show ydata
+?ydata
+ The `set ydata` commands sets y-axis data to timeseries (dates/times).
+ Please see `set xdata`.
+3 ydtics
+?commands set ydtics
+?commands unset ydtics
+?commands show ydtics
+?set ydtics
+?unset ydtics
+?show ydtics
+?ydtics
+?noydtics
+ The `set ydtics` command changes tics on the y axis to days of the week.
+ Please see `set xdtics` for details.
+3 ylabel
+?commands set ylabel
+?commands show ylabel
+?set ylabel
+?show ylabel
+?ylabel
+ This command sets the label for the y axis. Please see `set xlabel`.
+3 ymtics
+?commands set ymtics
+?commands unset ymtics
+?commands show ymtics
+?set ymtics
+?unset ymtics
+?show ymtics
+?ymtics
+?noymtics
+ The `set ymtics` command changes tics on the y axis to months of the year.
+ Please see `set xmtics` for details.
+3 yrange
+?commands set yrange
+?commands show yrange
+?set yrange
+?show yrange
+?yrange
+ The `set yrange` command sets the vertical range that will be displayed on
+ the y axis. Please see `set xrange` for details.
+3 ytics
+?commands set ytics
+?commands unset ytics
+?commands show ytics
+?set ytics
+?unset ytics
+?show ytics
+?ytics
+?noytics
+ The `set ytics` command controls major (labelled) tics on the y axis.
+ Please see `set xtics` for details.
+3 yzeroaxis
+?commands set yzeroaxis
+?commands unset yzeroaxis
+?commands show yzeroaxis
+?set yzeroaxis
+?unset yzeroaxis
+?show yzeroaxis
+?yzeroaxis
+?noyzeroaxis
+ The `set yzeroaxis` command draws a line at x = 0. For details,
+ please see `set zeroaxis`.
+3 zdata
+?commands set zdata
+?commands show zdata
+?set zdata
+?show zdata
+?zdata
+ The `set zdata` command sets zaxis data to timeseries (dates/times).
+ Please see `set xdata`.
+3 zdtics
+?commands set zdtics
+?commands unset zdtics
+?commands show zdtics
+?set zdtics
+?unset zdtics
+?show zdtics
+?zdtics
+?nozdtics
+ The `set zdtics` command changes tics on the z axis to days of the week.
+ Please see `set xdtics` for details.
+3 zzeroaxis
+?commands set zzeroaxis
+?commands unset zzeroaxis
+?commands show zzeroaxis
+?set zzeroaxis
+?unset zzeroaxis
+?show zzeroaxis
+?zzeroaxis
+?nozzeroaxis
+ The `set zzeroaxis` command draws a line through (x=0,y=0). This has no effect
+ on 2D plots, including splot with `set view map`. For details, please
+ see `set zeroaxis` and `set xyplane`.
+3 cbdata
+?commands set cbdata
+?commands show cbdata
+?set cbdata
+?show cbdata
+?cbdata
+ Set color box axis data to timeseries (dates/times). Please see `set xdata`.
+3 cbdtics
+?commands set cbdtics
+?commands unset cbdtics
+?commands show cbdtics
+?set cbdtics
+?unset cbdtics
+?show cbdtics
+?cbdtics
+?nocbdtics
+ The `set cbdtics` command changes tics on the color box axis to days of the
+ week. Please see `set xdtics` for details.
+3 zero
+?commands set zero
+?commands show zero
+?set zero
+?show zero
+?zero
+ The `zero` value is the default threshold for values approaching 0.0.
+
+ Syntax:
+ set zero <expression>
+ show zero
+
+ `gnuplot` will not plot a point if its imaginary part is greater in magnitude
+ than the `zero` threshold. This threshold is also used in various other
+ parts of `gnuplot` as a (crude) numerical-error threshold. The default
+ `zero` value is 1e-8. `zero` values larger than 1e-3 (the reciprocal of the
+ number of pixels in a typical bitmap display) should probably be avoided, but
+ it is not unreasonable to set `zero` to 0.0.
+3 zeroaxis
+?commands set zeroaxis
+?commands unset zeroaxis
+?commands show zeroaxis
+?set zeroaxis
+?unset zeroaxis
+?show zeroaxis
+?zeroaxis
+ The x axis may be drawn by `set xzeroaxis` and removed by `unset xzeroaxis`.
+ Similar commands behave similarly for the y, x2, y2, and z axes.
+
+ Syntax:
+ set {x|x2|y|y2|z}zeroaxis { {linestyle | ls <line_style>}
+ | { linetype | lt <line_type>}
+ { linewidth | lw <line_width>}}
+ unset {x|x2|y|y2|z}zeroaxis
+ show {x|y|z}zeroaxis
+
+
+ By default, these options are off. The selected zero axis is drawn
+ with a line of type <line_type> and width <line_width> (if supported
+ by the terminal driver currently in use), or a user-defined style
+ <line_style>.
+
+ If no linetype is specified, any zero axes selected will be drawn
+ using the axis linetype (linetype 0).
+
+ `set zeroaxis` is equivalent to `set xzeroaxis; set yzeroaxis`.
+ Note that the z-axis must be set separately using `set zzeroaxis`.
+
+ Examples:
+
+ To simply have the y=0 axis drawn visibly:
+
+ set xzeroaxis
+
+ If you want a thick line in a different color or pattern, instead:
+
+ set xzeroaxis linetype 3 linewidth 2.5
+3 zlabel
+?commands set zlabel
+?commands show zlabel
+?set zlabel
+?show zlabel
+?zlabel
+ This command sets the label for the z axis. Please see `set xlabel`.
+3 zmtics
+?commands set zmtics
+?commands unset zmtics
+?commands show zmtics
+?set zmtics
+?unset zmtics
+?show zmtics
+?zmtics
+?nozmtics
+ The `set zmtics` command changes tics on the z axis to months of the year.
+ Please see `set xmtics` for details.
+3 zrange
+?commands set zrange
+?commands show zrange
+?set zrange
+?show zrange
+?zrange
+ The `set zrange` command sets the range that will be displayed on the z axis.
+ The zrange is used only by `splot` and is ignored by `plot`. Please see
+ `set xrange` for details.
+3 ztics
+?commands set ztics
+?commands unset ztics
+?commands show ztics
+?set ztics
+?unset ztics
+?show ztics
+?ztics
+?noztics
+ The `set ztics` command controls major (labelled) tics on the z axis.
+ Please see `set xtics` for details.
+3 cblabel
+?commands set cblabel
+?commands show cblabel
+?set cblabel
+?show cblabel
+?cblabel
+ This command sets the label for the color box axis. Please see `set xlabel`.
+3 cbmtics
+?commands set cbmtics
+?commands unset cbmtics
+?commands show cbmtics
+?set cbmtics
+?unset cbmtics
+?show cbmtics
+?cbmtics
+?nocbmtics
+ The `set cbmtics` command changes tics on the color box axis to months of the
+ year. Please see `set xmtics` for details.
+3 cbrange
+?commands set cbrange
+?commands show cbrange
+?set cbrange
+?show cbrange
+?cbrange
+ The `set cbrange` command sets the range of values which are colored using
+ the current `palette` by styles `with pm3d`, `with image` and `with palette`.
+ Values outside of the color range use color of the nearest extreme.
+
+ If the cb-axis is autoscaled in `splot`, then the colorbox range is taken from
+ `zrange`. Points drawn in `splot ... pm3d|palette` can be filtered by using
+ different `zrange` and `cbrange`.
+
+ Please see `set xrange` for details on `set cbrange` syntax. See also
+ `set palette` and `set colorbox`.
+3 cbtics
+?commands set cbtics
+?commands unset cbtics
+?commands show cbtics
+?set cbtics
+?unset cbtics
+?show cbtics
+?cbtics
+?nocbtics
+ The `set cbtics` command controls major (labelled) tics on the color box axis.
+ Please see `set xtics` for details.
+2 shell
+?commands shell
+?shell
+ The `shell` command spawns an interactive shell. To return to `gnuplot`,
+ type `logout` if using VMS, `exit` or the END-OF-FILE character if using
+ Unix, `endcli` if using AmigaOS, or `exit` if using MS-DOS or OS/2.
+
+ There are two ways of spawning a shell command: using `system` command
+ or via `!` ($ if using VMS). The former command takes a string as a
+ parameter and thus it can be used anywhere among other gnuplot commands,
+ while the latter syntax requires to be the only command on the line. Control
+ will return immediately to `gnuplot` after this command is executed. For
+ example, in AmigaOS, MS-DOS or OS/2,
+
+ ! dir
+ or
+ system "dir"
+
+
+ prints a directory listing and then returns to `gnuplot`.
+
+
+ Other examples of the former syntax:
+ system "date"; set time; plot "a.dat"
+ print=1; if (print) replot; set out; system "lpr x.ps"
+
+ On an Atari, the `!` command first checks whether a shell is already loaded
+ and uses it, if available. This is practical if `gnuplot` is run from
+ `gulam`, for example.
+2 splot
+?commands splot
+?splot
+ `splot` is the command for drawing 3-d plots (well, actually projections on
+ a 2-d surface, but you knew that). It can create a plot from functions or
+ a data file in a manner very similar to the `plot` command.
+
+ See `plot` for features common to the `plot` command; only differences are
+ discussed in detail here. Note specifically `plot`'s `axes` option is not
+ available for `splot`.
+
+ Syntax:
+ splot {<ranges>}
+ <function> | "<datafile>" {datafile-modifiers}}
+ {<title-spec>} {with <style>}
+ {, {definitions,} <function> ...}
+
+ where either a <function> or the name of a data file enclosed in quotes is
+ supplied. The function can be a mathematical expression, or a triple of
+ mathematical expressions in parametric mode.
+
+ By default `splot` draws the xy plane completely below the plotted data.
+ The offset between the lowest ztic and the xy plane can be changed by `set
+ ticslevel`. The orientation of a `splot` projection is controlled by
+ `set view`. See `set view` and `set ticslevel` for more information.
+
+ The syntax for setting ranges on the `splot` command is the same as for
+ `plot`. In non-parametric mode, the order in which ranges must be given is
+ `xrange`, `yrange`, and `zrange`. In parametric mode, the order is `urange`,
+ `vrange`, `xrange`, `yrange`, and `zrange`.
+
+ The `title` option is the same as in `plot`. The operation of `with` is also
+ the same as in `plot`, except that the plotting styles available to `splot`
+ are limited to `lines`, `points`, `linespoints`, `dots`, and `impulses`; the
+ error-bar capabilities of `plot` are not available for `splot`.
+
+ The `datafile` options have more differences.
+
+ See also `show plot`.
+3 data-file
+?commands splot datafile
+?splot datafile
+?splot data-file
+ As for `plot`, discrete data contained in a file can be displayed by
+ specifying the name of the data file, enclosed in quotes, on the `splot`
+ command line.
+
+ Syntax:
+ splot '<file_name>' {binary <binary list>}
+ {matrix}
+ {index <index list>}
+ {every <every list>}
+ {using <using list>}
+
+ The special filenames `""` and `"-"` are permitted, as in `plot`.
+
+ In brief, `binary` and `matrix` indicate that the data are in a special
+ form, `index` selects which data sets in a multi-data-set file are to be
+ plotted, `every` specifies which datalines (subsets) within a single data
+ set are to be plotted, and `using` determines how the columns within a single
+ record are to be interpreted.
+
+ The options `index` and `every` behave the same way as with `plot`; `using`
+ does so also, except that the `using` list must provide three entries
+ instead of two.
+
+ The `plot` options `thru` and `smooth` are not available for `splot`, but
+ `cntrparam` and `dgrid3d` provide limited smoothing capabilities.
+
+ Data file organization is essentially the same as for `plot`, except that
+ each point is an (x,y,z) triple. If only a single value is provided, it
+ will be used for z, the datablock number will be used for y, and the index
+ of the data point in the datablock will be used for x. If two or four values
+ are provided, `gnuplot` uses the last value for calculating the color in
+ pm3d plots. Three values are interpreted as an (x,y,z) triple. Additional
+ values are generally used as errors, which can be used by `fit`.
+
+ Single blank records separate datablocks in a `splot` datafile; `splot`
+ treats datablocks as the equivalent of function y-isolines. No line will
+ join points separated by a blank record. If all datablocks contain the same
+ number of points, `gnuplot` will draw cross-isolines between datablocks,
+ connecting corresponding points. This is termed "grid data", and is required
+ for drawing a surface, for contouring (`set contour`) and hidden-line removal
+ (`set hidden3d`). See also `splot grid_data`.
+
+ It is no longer necessary to specify `parametric` mode for three-column
+ `splot`s.
+4 binary matrix
+?commands plot datafile binary matrix
+?commands splot datafile binary matrix
+?plot datafile matrix binary
+?splot datafile matrix binary
+?plot binary matrix
+?splot binary matrix
+?plot matrix binary
+?splot matrix binary
+?matrix binary
+?binary matrix
+?gpbin
+ Gnuplot can read matrix binary files by use of the option `binary` appearing
+ without keyword qualifications unique to general binary, i.e., `array`,
+ `record`, `format`, or `filetype`. Other general binary keywords for
+ translation should also apply to matrix binary. (See `binary general` for
+ more details.)
+
+ In previous versions, `gnuplot` dynamically detected binary data files. It
+ is now necessary to specify the keyword `binary` directly after the filename.
+
+ Single precision floats are stored in a binary file as follows:
+
+ <N+1> <y0> <y1> <y2> ... <yN>
+ <x0> <z0,0> <z0,1> <z0,2> ... <z0,N>
+ <x1> <z1,0> <z1,1> <z1,2> ... <z1,N>
+ : : : : ... :
+
+ which are converted into triplets:
+ <x0> <y0> <z0,0>
+ <x0> <y1> <z0,1>
+ <x0> <y2> <z0,2>
+ : : :
+ <x0> <yN> <z0,N>
+
+ <x1> <y0> <z1,0>
+ <x1> <y1> <z1,1>
+ : : :
+
+ These triplets are then converted into `gnuplot` iso-curves and then
+ `gnuplot` proceeds in the usual manner to do the rest of the plotting.
+
+ A collection of matrix and vector manipulation routines (in C) is provided
+ in `binary.c`. The routine to write binary data is
+
+ int fwrite_matrix(file,m,nrl,nrl,ncl,nch,row_title,column_title)
+
+ An example of using these routines is provided in the file `bf_test.c`, which
+ generates binary files for the demo file `demo/binary.dem`.
+
+ The `index` keyword is not supported, since the file format allows only one
+ surface per file. The `every` and `using` filters are supported. `using`
+ operates as if the data were read in the above triplet form.
+
+ See also `binary general` and
+
+^ <a href="http://www.gnuplot.info/demo/binary.html">
+ Binary File Splot Demo.
+^ </a>
+4 example datafile
+?commands splot datafile example
+?splot datafile example
+?splot example
+ A simple example of plotting a 3-d data file is
+
+ splot 'datafile.dat'
+
+ where the file "datafile.dat" might contain:
+
+ # The valley of the Gnu.
+ 0 0 10
+ 0 1 10
+ 0 2 10
+
+ 1 0 10
+ 1 1 5
+ 1 2 10
+
+ 2 0 10
+ 2 1 1
+ 2 2 10
+
+ 3 0 10
+ 3 1 0
+ 3 2 10
+
+ Note that "datafile.dat" defines a 4 by 3 grid ( 4 rows of 3 points each ).
+ Rows (datablocks) are separated by blank records.
+
+^ <img align=bottom src="http://www.gnuplot.info/doc/splot.gif" alt="[splot.gif]" width=640 height=480>
+ Note also that the x value is held constant within each dataline. If you
+ instead keep y constant, and plot with hidden-line removal enabled, you will
+ find that the surface is drawn 'inside-out'.
+
+ Actually for grid data it is not necessary to keep the x values constant
+ within a datablock, nor is it necessary to keep the same sequence of y
+ values. `gnuplot` requires only that the number of points be the same for
+ each datablock. However since the surface mesh, from which contours are
+ derived, connects sequentially corresponding points, the effect of an
+ irregular grid on a surface plot is unpredictable and should be examined
+ on a case-by-case basis.
+4 matrix_ascii
+?commands plot datafile matrix ascii
+?commands splot datafile matrix ascii
+?plot datafile matrix ascii
+?splot datafile matrix ascii
+?plot matrix ascii
+?splot matrix ascii
+?data-file matrix ascii
+?datafile matrix ascii
+?matrix ascii
+ The `matrix` keyword (without a sequent `binary` keyword) in
+ {s}plot 'a.dat' matrix
+ indicates that data are stored in an ascii numbers matrix format.
+
+ The z-values are read in a row at a time, i. e.,
+ z11 z12 z13 z14 ...
+ z21 z22 z23 z24 ...
+ z31 z32 z33 z34 ...
+ and so forth.
+
+ In 3D, the x- and y-indices of the matrix surface plot correspond to column
+ and row indices of the matrix, respectively, being enumerated from 0. You can
+ rescale or transform the axes as usual for a data file with three columns
+ by means of x=$1, y=$2, z=$3. For example
+ splot 'a.dat' matrix using (1+$1/100):(1+$2*10):3
+
+ A blank line or comment line ends the matrix, and starts a new surface mesh.
+ You can select among the meshes inside a file by the `index` option to the
+ `splot` command, as usual.
+
+ See `matrix` for examples of plotting rows and columns of the matrix in
+ a 2D plot.
+4 matrix
+?commands plot datafile matrix
+?commands splot datafile matrix
+?plot datafile matrix
+?splot datafile matrix
+?plot matrix
+?splot matrix
+?data-file matrix
+?datafile matrix
+?matrix
+ Datafile can be in an ascii or binary matrix format. The `matrix` flag
+ indicates that the file is ascii, the `binary` or `matrix binary` stands for
+ a binary format. For details, see `matrix ascii` and `matrix binary`.
+
+ Basic usage in `splot`:
+ splot 'a.dat' matrix
+ splot 'a.gpbin' {matrix} binary
+ Advanced usage in `splot`:
+ splot 'a.dat' matrix using 1:2:3
+ splot 'a.gpbin' {matrix} binary using 1:2:3
+ allows to transform the axes coordinates and the z-data independently.
+
+ Usage in `plot`:
+ plot `a.dat` matrix
+ plot `a.dat` matrix using 1:3
+ plot 'a.gpbin' {matrix} binary using 1:3
+ will plot rows of the matrix, while using 2:3 will plot matrix columns, and
+ using 1:2 the point coordinates (rather useless). Applying the `every` option
+ you can specify explicit rows and columns.
+
+ Example -- rescale axes of a matrix in an ascii file:
+ splot `a.dat` matrix using (1+$1):(1+$2*10):3
+
+ Example -- plot the 3rd row of a matrix in an ascii file:
+ plot 'a.dat' matrix using 1:3 every 1:999:1:2
+ (rows are enumerated from 0, thus 2 instead of 3).
+3 grid data
+?commands splot grid_data
+?splot grid_data
+?grid_data
+ The 3D routines are designed for points in a grid format, with one sample,
+ datapoint, at each mesh intersection; the datapoints may originate from
+ either evaluating a function, see `set isosamples`, or reading a datafile,
+ see `splot datafile`. The term "isoline" is applied to the mesh lines for
+ both functions and data. Note that the mesh need not be rectangular in x
+ and y, as it may be parameterized in u and v, see `set isosamples`.
+
+ However, `gnuplot` does not require that format. In the case of functions,
+ 'samples' need not be equal to 'isosamples', i.e., not every x-isoline
+ sample need intersect a y-isoline. In the case of data files, if there
+ are an equal number of scattered data points in each datablock, then
+ "isolines" will connect the points in a datablock, and "cross-isolines"
+ will connect the corresponding points in each datablock to generate a
+ "surface". In either case, contour and hidden3d modes may give different
+ plots than if the points were in the intended format. Scattered data can be
+ converted to a {different} grid format with `set dgrid3d`.
+
+ The contour code tests for z intensity along a line between a point on a
+ y-isoline and the corresponding point in the next y-isoline. Thus a `splot`
+ contour of a surface with samples on the x-isolines that do not coincide with
+ a y-isoline intersection will ignore such samples. Try:
+ set xrange [-pi/2:pi/2]; set yrange [-pi/2:pi/2]
+ set style function lp
+ set contour
+ set isosamples 10,10; set samples 10,10;
+ splot cos(x)*cos(y)
+ set samples 4,10; replot
+ set samples 10,4; replot
+
+3 splot overview
+?commands splot overview
+?splot overview
+ `splot` can display a surface as a collection of points, or by connecting
+ those points. As with `plot`, the points may be read from a data file or
+ result from evaluation of a function at specified intervals, see
+ `set isosamples`. The surface may be approximated by connecting the points
+ with straight line segments, see `set surface`, in which case the surface
+ can be made opaque with `set hidden3d.` The orientation from which the 3d
+ surface is viewed can be changed with `set view`.
+
+ Additionally, for points in a grid format, `splot` can interpolate points
+ having a common amplitude (see `set contour`) and can then connect those
+ new points to display contour lines, either directly with straight-line
+ segments or smoothed lines (see `set cntrparam`). Functions are already
+ evaluated in a grid format, determined by `set isosamples` and `set samples`,
+ while file data must either be in a grid format, as described in `data-file`,
+ or be used to generate a grid (see `set dgrid3d`).
+
+ Contour lines may be displayed either on the surface or projected onto the
+ base. The base projections of the contour lines may be written to a
+ file, and then read with `plot`, to take advantage of `plot`'s additional
+ formatting capabilities.
+2 system
+?commands system
+?system
+ `system "command"` executes "command" using the standard shell. See `shell`.
+ If called as a function, `system("command")` returns the resulting character
+ stream from stdout as a string. One optional trailing newline is ignored.
+
+ This can be used to import external functions into gnuplot scripts:
+
+ f(x) = real(system(sprintf("somecommand %f", x)))
+2 test
+?commands test
+?test palette
+?test
+ This command graphically tests or presents terminal and palette capabilities.
+
+ Syntax:
+ test {terminal | palette [rgb|rbg|grb|gbr|brg|bgr]}
+
+ `test` or `test terminal` creates a display of line and point styles and other
+ useful things appropriate for and supported by the `terminal` you are just
+ using.
+
+ `test palette` draws graphically profiles R(z),G(z),B(z), where 0<=z<=1, as
+ calculated by the current color `palette`. In other words, it is a beautiful
+ plot you would have to do yourself with the result of `show palette palette 256 float`.
+ The optional parameter, a permutation of letters rgb, determines the sequence of
+ r,g,b profiles drawn one after the other --- try this yourself for `set palette
+ gray`. The default sequence is rgb.
+2 undefine
+?commands undefine
+?undefine
+ Clear one or more previously defined user variables. This is useful in order
+ to reset the state of a script containing an initialization test.
+
+ Example:
+
+ undefine foo foo1 foo2
+ if (!exists("foo")) load "initialize.gp"
+
+2 unset
+?commands unset
+?unset
+ Options set using the `set` command may be returned to their default state by
+ issuing the corresponding `unset` command.
+
+ Example:
+ set xtics mirror rotate by -45 0,10,100
+ ...
+ unset xtics
+
+2 update
+?commands update
+?update
+ This command writes the current values of the fit parameters into the given
+ file, formatted as an initial-value file (as described in the `fit`section).
+ This is useful for saving the current values for later use or for restarting
+ a converged or stopped fit.
+
+ Syntax:
+ update <filename> {<filename>}
+
+ If a second filename is supplied, the updated values are written to this
+ file, and the original parameter file is left unmodified.
+
+ Otherwise, if the file already exists, `gnuplot` first renames it by
+ appending `.old` and then opens a new file. That is, "`update 'fred'`"
+ behaves the same as "`!rename fred fred.old; update 'fred.old' 'fred'`".
+ [On DOS and other systems that use the twelve-character "filename.ext"
+ naming convention, "ext" will be "`old`" and "filename" will be related
+ (hopefully recognizably) to the initial name. Renaming is not done at all
+ on VMS systems, since they use file-versioning.]
+
+ Please see `fit` for more information.
+1 Terminal types
+^ <h2> Terminal Types </h2>
+2 terminal
+?terminal
+?term
+ Gnuplot supports a large number of output formats. These are selected by
+ choosing an appropriate terminal type, possibly with additional modifying
+ options. See `set terminal`.
+
+ This document may describe terminal types that are not available to you
+ because they were not configured or installed on your system. To see a list of
+ terminals available on a particular gnuplot installation, type 'set terminal'
+ with no modifiers.
+<3 -- all terminal stuff is pulled from the .trm files
+1 Graphical User Interfaces
+?graphical user interfaces
+?gui's
+ Several graphical user interfaces have been written for `gnuplot` and one for
+ win32 is included in this distribution. In addition, there is a Python
+ interface at
+^ <a href="http://py-gnuplot.darwinports.com/">
+ http://py-gnuplot.darwinports.com/
+^ </a>
+
+ Also several X11 interfaces exist.
+ One of them is called xgfe. It uses the Qt library and can be found on
+^ <a href="http://www.flash.net/~dmishee/xgfe/xgfe.html">
+ http://www.flash.net/~dmishee/xgfe/xgfe.html
+^ </a>
+
+ In addition three Tcl/Tk located at the usual Tcl/Tk repositories exist.
+
+ Bruce Ravel (ravel@phys.washington.edu) has written a new version of
+ gnuplot-mode for GNU emacs and XEmacs. This version is based on
+ the gnuplot.el file by Gershon Elber.
+ While the gnuplot CVS repository has its own copy the most recent
+ version of this package is available from
+^ <a href="http://feff.phys.washington.edu/~ravel/software/gnuplot-mode/">
+ http://feff.phys.washington.edu/~ravel/software/gnuplot-mode/
+^ </a>
+
+1 Bugs
+?bugs
+ Bugs reported since the current release as well as older ones
+ may be located via the official distribution site on SourceForge.
+
+ Please e-mail bug reports to the gnuplot-bugs mailing list.
+ Or upload the report to the gnuplot web site on SourceForge.
+ Please give complete information on the version of gnuplot you are using
+ and, if possible, a test script that demonstrates the bug.
+ See `Seeking-assistance`.
+
+ The sections below list problems known to be present in gnuplot version 4.2 at
+ the time of release. Some of these are actually bugs in external support
+ libraries and may have been fixed indepently of any changes in gnuplot.
+
+2 Gnuplot limitations
+?bugs gnuplot
+=gamma
+=bessel
+=timefmt
+=load
+=nohidden3d
+ Floating point exceptions (floating point number too large/small, divide by
+ zero, etc.) may occasionally be generated by user defined functions. Some of
+ the demos in particular may cause numbers to exceed the floating point range.
+ Whether the system ignores such exceptions (in which case `gnuplot` labels
+ the corresponding point as undefined) or aborts `gnuplot` depends on the
+ compiler/runtime environment.
+
+ The gamma and bessel functions do not work for complex arguments.
+
+ If a command line contains a "load" command, then anything on the line after
+ the "load <filename>" is ignored.
+
+ Only one color palette at a time is active for any given x11 plot window.
+ This means that multiplots whose constituent plots use different palettes
+ will not display correctly in x11.
+
+ Coordinates specified as "time" wrap at 24 hours, and have a precision limited
+ to 1 second. This is in particular a limitation in using time format to
+ handle geographic coordinates.
+
+ Error bars are not handled properly in polar/spherical coordinate plot modes.
+
+ The 'nohidden3d' option that is supposed to exempt individual plots from the
+ global property 'set hidden3d' does not work for parametric curves.
+
+2 External libraries
+?bugs external_libraries
+=libgd
+=svgalib
+=locale
+=internationalization
+=pdf
+ External library GD (used by PNG/JPEG/GIF drivers):
+ Versions of libgd through 2.0.33 contain various bugs in mapping the characters
+ of Adobe's Symbol font. Also it is possible to trigger a library segfault if
+ an anti-aliased line crosses an upper corner of the canvas.
+
+ External library PDFlib (used by PDF driver):
+ Gnuplot can be linked against libpdf versions 4, 5, or 6. However, these
+ versions differ in their handling of piped I/O. Therefore gnuplot scripts
+ using piped output to PDF may work only for some versions of PDFlib.
+
+ External library svgalib (used by linux and vgagl driver):
+ Requires gnuplot to be suid root (bad!) and has many bugs that are specific
+ to the video card or graphics driver used in X11.
+
+ Internationalization (locale settings):
+ Gnuplot uses the C runtime library routine setlocale() to control
+ locale-specific formatting of input and output number, times, and date strings.
+ The locales available, and the level of support for locale features such as
+ "thousands' grouping separator", depend on the internationalization support
+ provided by your individual machine.
projects / gnuplot / blobdiff