opencv/3rdparty/lapack/srot.c

78 lines
1.4 KiB
C

#include "clapack.h"
/* Subroutine */ int srot_(integer *n, real *sx, integer *incx, real *sy,
integer *incy, real *c__, real *s)
{
/* System generated locals */
integer i__1;
/* Local variables */
integer i__, ix, iy;
real stemp;
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* applies a plane rotation. */
/* Further Details */
/* =============== */
/* jack dongarra, linpack, 3/11/78. */
/* modified 12/3/93, array(1) declarations changed to array(*) */
/* .. Local Scalars .. */
/* .. */
/* Parameter adjustments */
--sy;
--sx;
/* Function Body */
if (*n <= 0) {
return 0;
}
if (*incx == 1 && *incy == 1) {
goto L20;
}
/* code for unequal increments or equal increments not equal */
/* to 1 */
ix = 1;
iy = 1;
if (*incx < 0) {
ix = (-(*n) + 1) * *incx + 1;
}
if (*incy < 0) {
iy = (-(*n) + 1) * *incy + 1;
}
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
stemp = *c__ * sx[ix] + *s * sy[iy];
sy[iy] = *c__ * sy[iy] - *s * sx[ix];
sx[ix] = stemp;
ix += *incx;
iy += *incy;
/* L10: */
}
return 0;
/* code for both increments equal to 1 */
L20:
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
stemp = *c__ * sx[i__] + *s * sy[i__];
sy[i__] = *c__ * sy[i__] - *s * sx[i__];
sx[i__] = stemp;
/* L30: */
}
return 0;
} /* srot_ */