opencv/3rdparty/lapack/slaset.c

140 lines
3.5 KiB
C

#include "clapack.h"
/* Subroutine */ int slaset_(char *uplo, integer *m, integer *n, real *alpha,
real *beta, real *a, integer *lda)
{
/* System generated locals */
integer a_dim1, a_offset, i__1, i__2, i__3;
/* Local variables */
integer i__, j;
extern logical lsame_(char *, char *);
/* -- LAPACK auxiliary routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SLASET initializes an m-by-n matrix A to BETA on the diagonal and */
/* ALPHA on the offdiagonals. */
/* Arguments */
/* ========= */
/* UPLO (input) CHARACTER*1 */
/* Specifies the part of the matrix A to be set. */
/* = 'U': Upper triangular part is set; the strictly lower */
/* triangular part of A is not changed. */
/* = 'L': Lower triangular part is set; the strictly upper */
/* triangular part of A is not changed. */
/* Otherwise: All of the matrix A is set. */
/* M (input) INTEGER */
/* The number of rows of the matrix A. M >= 0. */
/* N (input) INTEGER */
/* The number of columns of the matrix A. N >= 0. */
/* ALPHA (input) REAL */
/* The constant to which the offdiagonal elements are to be set. */
/* BETA (input) REAL */
/* The constant to which the diagonal elements are to be set. */
/* A (input/output) REAL array, dimension (LDA,N) */
/* On exit, the leading m-by-n submatrix of A is set as follows: */
/* if UPLO = 'U', A(i,j) = ALPHA, 1<=i<=j-1, 1<=j<=n, */
/* if UPLO = 'L', A(i,j) = ALPHA, j+1<=i<=m, 1<=j<=n, */
/* otherwise, A(i,j) = ALPHA, 1<=i<=m, 1<=j<=n, i.ne.j, */
/* and, for all UPLO, A(i,i) = BETA, 1<=i<=min(m,n). */
/* LDA (input) INTEGER */
/* The leading dimension of the array A. LDA >= max(1,M). */
/* ===================================================================== */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
/* Function Body */
if (lsame_(uplo, "U")) {
/* Set the strictly upper triangular or trapezoidal part of the */
/* array to ALPHA. */
i__1 = *n;
for (j = 2; j <= i__1; ++j) {
/* Computing MIN */
i__3 = j - 1;
i__2 = min(i__3,*m);
for (i__ = 1; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = *alpha;
/* L10: */
}
/* L20: */
}
} else if (lsame_(uplo, "L")) {
/* Set the strictly lower triangular or trapezoidal part of the */
/* array to ALPHA. */
i__1 = min(*m,*n);
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = j + 1; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = *alpha;
/* L30: */
}
/* L40: */
}
} else {
/* Set the leading m-by-n submatrix to ALPHA. */
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
a[i__ + j * a_dim1] = *alpha;
/* L50: */
}
/* L60: */
}
}
/* Set the first min(M,N) diagonal elements to BETA. */
i__1 = min(*m,*n);
for (i__ = 1; i__ <= i__1; ++i__) {
a[i__ + i__ * a_dim1] = *beta;
/* L70: */
}
return 0;
/* End of SLASET */
} /* slaset_ */