/* csrot.f -- translated by f2c (version 20061008).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
#include "blaswrap.h"
/* Subroutine */ int csrot_(integer *n, complex *cx, integer *incx, complex *
cy, integer *incy, real *c__, real *s)
{
/* System generated locals */
integer i__1, i__2, i__3, i__4;
complex q__1, q__2, q__3;
/* Local variables */
integer i__, ix, iy;
complex ctemp;
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* Applies a plane rotation, where the cos and sin (c and s) are real */
/* and the vectors cx and cy are complex. */
/* jack dongarra, linpack, 3/11/78. */
/* Arguments */
/* ========== */
/* N (input) INTEGER */
/* On entry, N specifies the order of the vectors cx and cy. */
/* N must be at least zero. */
/* Unchanged on exit. */
/* CX (input) COMPLEX array, dimension at least */
/* ( 1 + ( N - 1 )*abs( INCX ) ). */
/* Before entry, the incremented array CX must contain the n */
/* element vector cx. On exit, CX is overwritten by the updated */
/* vector cx. */
/* INCX (input) INTEGER */
/* On entry, INCX specifies the increment for the elements of */
/* CX. INCX must not be zero. */
/* Unchanged on exit. */
/* CY (input) COMPLEX array, dimension at least */
/* ( 1 + ( N - 1 )*abs( INCY ) ). */
/* Before entry, the incremented array CY must contain the n */
/* element vector cy. On exit, CY is overwritten by the updated */
/* vector cy. */
/* INCY (input) INTEGER */
/* On entry, INCY specifies the increment for the elements of */
/* CY. INCY must not be zero. */
/* Unchanged on exit. */
/* C (input) REAL */
/* On entry, C specifies the cosine, cos. */
/* Unchanged on exit. */
/* S (input) REAL */
/* On entry, S specifies the sine, sin. */
/* Unchanged on exit. */
/* ===================================================================== */
/* .. Local Scalars .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--cy;
--cx;
/* 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__) {
i__2 = ix;
q__2.r = *c__ * cx[i__2].r, q__2.i = *c__ * cx[i__2].i;
i__3 = iy;
q__3.r = *s * cy[i__3].r, q__3.i = *s * cy[i__3].i;
q__1.r = q__2.r + q__3.r, q__1.i = q__2.i + q__3.i;
ctemp.r = q__1.r, ctemp.i = q__1.i;
i__2 = iy;
i__3 = iy;
q__2.r = *c__ * cy[i__3].r, q__2.i = *c__ * cy[i__3].i;
i__4 = ix;
q__3.r = *s * cx[i__4].r, q__3.i = *s * cx[i__4].i;
q__1.r = q__2.r - q__3.r, q__1.i = q__2.i - q__3.i;
cy[i__2].r = q__1.r, cy[i__2].i = q__1.i;
i__2 = ix;
cx[i__2].r = ctemp.r, cx[i__2].i = ctemp.i;
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__) {
i__2 = i__;
q__2.r = *c__ * cx[i__2].r, q__2.i = *c__ * cx[i__2].i;
i__3 = i__;
q__3.r = *s * cy[i__3].r, q__3.i = *s * cy[i__3].i;
q__1.r = q__2.r + q__3.r, q__1.i = q__2.i + q__3.i;
ctemp.r = q__1.r, ctemp.i = q__1.i;
i__2 = i__;
i__3 = i__;
q__2.r = *c__ * cy[i__3].r, q__2.i = *c__ * cy[i__3].i;
i__4 = i__;
q__3.r = *s * cx[i__4].r, q__3.i = *s * cx[i__4].i;
q__1.r = q__2.r - q__3.r, q__1.i = q__2.i - q__3.i;
cy[i__2].r = q__1.r, cy[i__2].i = q__1.i;
i__2 = i__;
cx[i__2].r = ctemp.r, cx[i__2].i = ctemp.i;
/* L30: */
}
return 0;
} /* csrot_ */
