Update to 2.0.0 tree from current Fremantle build

[opencv] / 3rdparty / lapack / dlassq.c

diff --git a/3rdparty/lapack/dlassq.c b/3rdparty/lapack/dlassq.c
new file mode 100644 (file)
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+++ b/3rdparty/lapack/dlassq.c
@@ -0,0 +1,103 @@
+#include "clapack.h"
+
+/* Subroutine */ int dlassq_(integer *n, doublereal *x, integer *incx, 
+       doublereal *scale, doublereal *sumsq)
+{
+    /* System generated locals */
+    integer i__1, i__2;
+    doublereal d__1;
+
+    /* Local variables */
+    integer ix;
+    doublereal absxi;
+
+
+/*  -- LAPACK auxiliary routine (version 3.1) -- */
+/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/*     November 2006 */
+
+/*     .. Scalar Arguments .. */
+/*     .. */
+/*     .. Array Arguments .. */
+/*     .. */
+
+/*  Purpose */
+/*  ======= */
+
+/*  DLASSQ  returns the values  scl  and  smsq  such that */
+
+/*     ( scl**2 )*smsq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq, */
+
+/*  where  x( i ) = X( 1 + ( i - 1 )*INCX ). The value of  sumsq  is */
+/*  assumed to be non-negative and  scl  returns the value */
+
+/*     scl = max( scale, abs( x( i ) ) ). */
+
+/*  scale and sumsq must be supplied in SCALE and SUMSQ and */
+/*  scl and smsq are overwritten on SCALE and SUMSQ respectively. */
+
+/*  The routine makes only one pass through the vector x. */
+
+/*  Arguments */
+/*  ========= */
+
+/*  N       (input) INTEGER */
+/*          The number of elements to be used from the vector X. */
+
+/*  X       (input) DOUBLE PRECISION array, dimension (N) */
+/*          The vector for which a scaled sum of squares is computed. */
+/*             x( i )  = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n. */
+
+/*  INCX    (input) INTEGER */
+/*          The increment between successive values of the vector X. */
+/*          INCX > 0. */
+
+/*  SCALE   (input/output) DOUBLE PRECISION */
+/*          On entry, the value  scale  in the equation above. */
+/*          On exit, SCALE is overwritten with  scl , the scaling factor */
+/*          for the sum of squares. */
+
+/*  SUMSQ   (input/output) DOUBLE PRECISION */
+/*          On entry, the value  sumsq  in the equation above. */
+/*          On exit, SUMSQ is overwritten with  smsq , the basic sum of */
+/*          squares from which  scl  has been factored out. */
+
+/* ===================================================================== */
+
+/*     .. Parameters .. */
+/*     .. */
+/*     .. Local Scalars .. */
+/*     .. */
+/*     .. Intrinsic Functions .. */
+/*     .. */
+/*     .. Executable Statements .. */
+
+    /* Parameter adjustments */
+    --x;
+
+    /* Function Body */
+    if (*n > 0) {
+       i__1 = (*n - 1) * *incx + 1;
+       i__2 = *incx;
+       for (ix = 1; i__2 < 0 ? ix >= i__1 : ix <= i__1; ix += i__2) {
+           if (x[ix] != 0.) {
+               absxi = (d__1 = x[ix], abs(d__1));
+               if (*scale < absxi) {
+/* Computing 2nd power */
+                   d__1 = *scale / absxi;
+                   *sumsq = *sumsq * (d__1 * d__1) + 1;
+                   *scale = absxi;
+               } else {
+/* Computing 2nd power */
+                   d__1 = absxi / *scale;
+                   *sumsq += d__1 * d__1;
+               }
+           }
+/* L10: */
+       }
+    }
+    return 0;
+
+/*     End of DLASSQ */
+
+} /* dlassq_ */