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lammps/lib/linalg/zdrot.cpp
Axel Kohlmeyer 1e8b2ad5a0 whitespace fixes
2022-12-28 13:48:43 -05:00

214 lines
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/* fortran/zdrot.f -- translated by f2c (version 20200916).
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
*/
#ifdef __cplusplus
extern "C" {
#endif
#include "lmp_f2c.h"
/* > \brief \b ZDROT */
/* =========== DOCUMENTATION =========== */
/* Online html documentation available at */
/* http://www.netlib.org/lapack/explore-html/ */
/* Definition: */
/* =========== */
/* SUBROUTINE ZDROT( N, ZX, INCX, ZY, INCY, C, S ) */
/* .. Scalar Arguments .. */
/* INTEGER INCX, INCY, N */
/* DOUBLE PRECISION C, S */
/* .. */
/* .. Array Arguments .. */
/* COMPLEX*16 ZX( * ), ZY( * ) */
/* .. */
/* > \par Purpose: */
/* ============= */
/* > */
/* > \verbatim */
/* > */
/* > 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. */
/* > \endverbatim */
/* Arguments: */
/* ========== */
/* > \param[in] N */
/* > \verbatim */
/* > N is INTEGER */
/* > On entry, N specifies the order of the vectors cx and cy. */
/* > N must be at least zero. */
/* > \endverbatim */
/* > */
/* > \param[in,out] ZX */
/* > \verbatim */
/* > ZX is COMPLEX*16 array, dimension at least */
/* > ( 1 + ( N - 1 )*abs( INCX ) ). */
/* > Before entry, the incremented array ZX must contain the n */
/* > element vector cx. On exit, ZX is overwritten by the updated */
/* > vector cx. */
/* > \endverbatim */
/* > */
/* > \param[in] INCX */
/* > \verbatim */
/* > INCX is INTEGER */
/* > On entry, INCX specifies the increment for the elements of */
/* > ZX. INCX must not be zero. */
/* > \endverbatim */
/* > */
/* > \param[in,out] ZY */
/* > \verbatim */
/* > ZY is COMPLEX*16 array, dimension at least */
/* > ( 1 + ( N - 1 )*abs( INCY ) ). */
/* > Before entry, the incremented array ZY must contain the n */
/* > element vector cy. On exit, ZY is overwritten by the updated */
/* > vector cy. */
/* > \endverbatim */
/* > */
/* > \param[in] INCY */
/* > \verbatim */
/* > INCY is INTEGER */
/* > On entry, INCY specifies the increment for the elements of */
/* > ZY. INCY must not be zero. */
/* > \endverbatim */
/* > */
/* > \param[in] C */
/* > \verbatim */
/* > C is DOUBLE PRECISION */
/* > On entry, C specifies the cosine, cos. */
/* > \endverbatim */
/* > */
/* > \param[in] S */
/* > \verbatim */
/* > S is DOUBLE PRECISION */
/* > On entry, S specifies the sine, sin. */
/* > \endverbatim */
/* Authors: */
/* ======== */
/* > \author Univ. of Tennessee */
/* > \author Univ. of California Berkeley */
/* > \author Univ. of Colorado Denver */
/* > \author NAG Ltd. */
/* > \ingroup complex16_blas_level1 */
/* ===================================================================== */
/* Subroutine */ int zdrot_(integer *n, doublecomplex *zx, integer *incx,
doublecomplex *zy, integer *incy, doublereal *c__, doublereal *s)
{
/* System generated locals */
integer i__1, i__2, i__3, i__4;
doublecomplex z__1, z__2, z__3;
/* Local variables */
integer i__, ix, iy;
doublecomplex ctemp;
/* -- Reference BLAS level1 routine -- */
/* -- Reference BLAS is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ===================================================================== */
/* .. Local Scalars .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--zy;
--zx;
/* Function Body */
if (*n <= 0) {
return 0;
}
if (*incx == 1 && *incy == 1) {
/* code for both increments equal to 1 */
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
i__2 = i__;
z__2.r = *c__ * zx[i__2].r, z__2.i = *c__ * zx[i__2].i;
i__3 = i__;
z__3.r = *s * zy[i__3].r, z__3.i = *s * zy[i__3].i;
z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i;
ctemp.r = z__1.r, ctemp.i = z__1.i;
i__2 = i__;
i__3 = i__;
z__2.r = *c__ * zy[i__3].r, z__2.i = *c__ * zy[i__3].i;
i__4 = i__;
z__3.r = *s * zx[i__4].r, z__3.i = *s * zx[i__4].i;
z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i;
zy[i__2].r = z__1.r, zy[i__2].i = z__1.i;
i__2 = i__;
zx[i__2].r = ctemp.r, zx[i__2].i = ctemp.i;
}
} else {
/* 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;
z__2.r = *c__ * zx[i__2].r, z__2.i = *c__ * zx[i__2].i;
i__3 = iy;
z__3.r = *s * zy[i__3].r, z__3.i = *s * zy[i__3].i;
z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i;
ctemp.r = z__1.r, ctemp.i = z__1.i;
i__2 = iy;
i__3 = iy;
z__2.r = *c__ * zy[i__3].r, z__2.i = *c__ * zy[i__3].i;
i__4 = ix;
z__3.r = *s * zx[i__4].r, z__3.i = *s * zx[i__4].i;
z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i;
zy[i__2].r = z__1.r, zy[i__2].i = z__1.i;
i__2 = ix;
zx[i__2].r = ctemp.r, zx[i__2].i = ctemp.i;
ix += *incx;
iy += *incy;
}
}
return 0;
/* End of ZDROT */
} /* zdrot_ */
#ifdef __cplusplus
}
#endif