#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_ */