--- /dev/null
+
+/* -- translated by f2c (version 19940927).
+ You must link the resulting object file with the libraries:
+ -lf2c -lm (in that order)
+*/
+
+#include "clapack.h"
+
+/* Subroutine */ int dsyr_(char *uplo, integer *n, doublereal *alpha,
+ doublereal *x, integer *incx, doublereal *a, integer *lda)
+{
+
+
+ /* System generated locals */
+ integer a_dim1, a_offset, i__1, i__2;
+
+ /* Local variables */
+ static integer info;
+ static doublereal temp;
+ static integer i, j;
+ extern logical lsame_(char *, char *);
+ static integer ix, jx, kx;
+ extern /* Subroutine */ int xerbla_(char *, integer *);
+
+
+/* Purpose
+ =======
+
+ DSYR performs the symmetric rank 1 operation
+
+ A := alpha*x*x' + A,
+
+ where alpha is a real scalar, x is an n element vector and A is an
+ n by n symmetric matrix.
+
+ Parameters
+ ==========
+
+ UPLO - CHARACTER*1.
+ On entry, UPLO specifies whether the upper or lower
+ triangular part of the array A is to be referenced as
+ follows:
+
+ UPLO = 'U' or 'u' Only the upper triangular part of A
+ is to be referenced.
+
+ UPLO = 'L' or 'l' Only the lower triangular part of A
+ is to be referenced.
+
+ Unchanged on exit.
+
+ N - INTEGER.
+ On entry, N specifies the order of the matrix A.
+ N must be at least zero.
+ Unchanged on exit.
+
+ ALPHA - DOUBLE PRECISION.
+ On entry, ALPHA specifies the scalar alpha.
+ Unchanged on exit.
+
+ X - DOUBLE PRECISION array of dimension at least
+ ( 1 + ( n - 1 )*abs( INCX ) ).
+ Before entry, the incremented array X must contain the n
+ element vector x.
+ Unchanged on exit.
+
+ INCX - INTEGER.
+ On entry, INCX specifies the increment for the elements of
+ X. INCX must not be zero.
+ Unchanged on exit.
+
+ A - DOUBLE PRECISION array of DIMENSION ( LDA, n ).
+ Before entry with UPLO = 'U' or 'u', the leading n by n
+ upper triangular part of the array A must contain the upper
+
+ triangular part of the symmetric matrix and the strictly
+ lower triangular part of A is not referenced. On exit, the
+ upper triangular part of the array A is overwritten by the
+ upper triangular part of the updated matrix.
+ Before entry with UPLO = 'L' or 'l', the leading n by n
+ lower triangular part of the array A must contain the lower
+
+ triangular part of the symmetric matrix and the strictly
+ upper triangular part of A is not referenced. On exit, the
+ lower triangular part of the array A is overwritten by the
+ lower triangular part of the updated matrix.
+
+ LDA - INTEGER.
+ On entry, LDA specifies the first dimension of A as declared
+
+ in the calling (sub) program. LDA must be at least
+ max( 1, n ).
+ Unchanged on exit.
+
+
+ Level 2 Blas routine.
+
+ -- Written on 22-October-1986.
+ Jack Dongarra, Argonne National Lab.
+ Jeremy Du Croz, Nag Central Office.
+ Sven Hammarling, Nag Central Office.
+ Richard Hanson, Sandia National Labs.
+
+
+
+ Test the input parameters.
+
+
+ Parameter adjustments
+ Function Body */
+#define X(I) x[(I)-1]
+
+#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]
+
+ info = 0;
+ if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
+ info = 1;
+ } else if (*n < 0) {
+ info = 2;
+ } else if (*incx == 0) {
+ info = 5;
+ } else if (*lda < max(1,*n)) {
+ info = 7;
+ }
+ if (info != 0) {
+ xerbla_("DSYR ", &info);
+ return 0;
+ }
+
+/* Quick return if possible. */
+
+ if (*n == 0 || *alpha == 0.) {
+ return 0;
+ }
+
+/* Set the start point in X if the increment is not unity. */
+
+ if (*incx <= 0) {
+ kx = 1 - (*n - 1) * *incx;
+ } else if (*incx != 1) {
+ kx = 1;
+ }
+
+/* Start the operations. In this version the elements of A are
+ accessed sequentially with one pass through the triangular part
+ of A. */
+
+ if (lsame_(uplo, "U")) {
+
+/* Form A when A is stored in upper triangle. */
+
+ if (*incx == 1) {
+ i__1 = *n;
+ for (j = 1; j <= *n; ++j) {
+ if (X(j) != 0.) {
+ temp = *alpha * X(j);
+ i__2 = j;
+ for (i = 1; i <= j; ++i) {
+ A(i,j) += X(i) * temp;
+/* L10: */
+ }
+ }
+/* L20: */
+ }
+ } else {
+ jx = kx;
+ i__1 = *n;
+ for (j = 1; j <= *n; ++j) {
+ if (X(jx) != 0.) {
+ temp = *alpha * X(jx);
+ ix = kx;
+ i__2 = j;
+ for (i = 1; i <= j; ++i) {
+ A(i,j) += X(ix) * temp;
+ ix += *incx;
+/* L30: */
+ }
+ }
+ jx += *incx;
+/* L40: */
+ }
+ }
+ } else {
+
+/* Form A when A is stored in lower triangle. */
+
+ if (*incx == 1) {
+ i__1 = *n;
+ for (j = 1; j <= *n; ++j) {
+ if (X(j) != 0.) {
+ temp = *alpha * X(j);
+ i__2 = *n;
+ for (i = j; i <= *n; ++i) {
+ A(i,j) += X(i) * temp;
+/* L50: */
+ }
+ }
+/* L60: */
+ }
+ } else {
+ jx = kx;
+ i__1 = *n;
+ for (j = 1; j <= *n; ++j) {
+ if (X(jx) != 0.) {
+ temp = *alpha * X(jx);
+ ix = jx;
+ i__2 = *n;
+ for (i = j; i <= *n; ++i) {
+ A(i,j) += X(ix) * temp;
+ ix += *incx;
+/* L70: */
+ }
+ }
+ jx += *incx;
+/* L80: */
+ }
+ }
+ }
+
+ return 0;
+
+/* End of DSYR . */
+
+} /* dsyr_ */
+
projects / opencv / blobdiff