ICODE-ADC/lammps
4
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
1e8b2ad5a07fd32e63b55d7d52e1264829b96bb4
lammps/lib/linalg/zlarf.cpp
Axel Kohlmeyer 1e8b2ad5a0 whitespace fixes
2022-12-28 13:48:43 -05:00

284 lines
8.4 KiB
C++
Raw Blame History

/* fortran/zlarf.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"
/* Table of constant values */
static doublecomplex c_b1 = {1.,0.};
static doublecomplex c_b2 = {0.,0.};
static integer c__1 = 1;
/* > \brief \b ZLARF applies an elementary reflector to a general rectangular matrix. */
/* =========== DOCUMENTATION =========== */
/* Online html documentation available at */
/* http://www.netlib.org/lapack/explore-html/ */
/* > \htmlonly */
/* > Download ZLARF + dependencies */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zlarf.f
"> */
/* > [TGZ]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zlarf.f
"> */
/* > [ZIP]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zlarf.f
"> */
/* > [TXT]</a> */
/* > \endhtmlonly */
/* Definition: */
/* =========== */
/* SUBROUTINE ZLARF( SIDE, M, N, V, INCV, TAU, C, LDC, WORK ) */
/* .. Scalar Arguments .. */
/* CHARACTER SIDE */
/* INTEGER INCV, LDC, M, N */
/* COMPLEX*16 TAU */
/* .. */
/* .. Array Arguments .. */
/* COMPLEX*16 C( LDC, * ), V( * ), WORK( * ) */
/* .. */
/* > \par Purpose: */
/* ============= */
/* > */
/* > \verbatim */
/* > */
/* > ZLARF applies a complex elementary reflector H to a complex M-by-N */
/* > matrix C, from either the left or the right. H is represented in the */
/* > form */
/* > */
/* > H = I - tau * v * v**H */
/* > */
/* > where tau is a complex scalar and v is a complex vector. */
/* > */
/* > If tau = 0, then H is taken to be the unit matrix. */
/* > */
/* > To apply H**H, supply conjg(tau) instead */
/* > tau. */
/* > \endverbatim */
/* Arguments: */
/* ========== */
/* > \param[in] SIDE */
/* > \verbatim */
/* > SIDE is CHARACTER*1 */
/* > = 'L': form H * C */
/* > = 'R': form C * H */
/* > \endverbatim */
/* > */
/* > \param[in] M */
/* > \verbatim */
/* > M is INTEGER */
/* > The number of rows of the matrix C. */
/* > \endverbatim */
/* > */
/* > \param[in] N */
/* > \verbatim */
/* > N is INTEGER */
/* > The number of columns of the matrix C. */
/* > \endverbatim */
/* > */
/* > \param[in] V */
/* > \verbatim */
/* > V is COMPLEX*16 array, dimension */
/* > (1 + (M-1)*abs(INCV)) if SIDE = 'L' */
/* > or (1 + (N-1)*abs(INCV)) if SIDE = 'R' */
/* > The vector v in the representation of H. V is not used if */
/* > TAU = 0. */
/* > \endverbatim */
/* > */
/* > \param[in] INCV */
/* > \verbatim */
/* > INCV is INTEGER */
/* > The increment between elements of v. INCV <> 0. */
/* > \endverbatim */
/* > */
/* > \param[in] TAU */
/* > \verbatim */
/* > TAU is COMPLEX*16 */
/* > The value tau in the representation of H. */
/* > \endverbatim */
/* > */
/* > \param[in,out] C */
/* > \verbatim */
/* > C is COMPLEX*16 array, dimension (LDC,N) */
/* > On entry, the M-by-N matrix C. */
/* > On exit, C is overwritten by the matrix H * C if SIDE = 'L', */
/* > or C * H if SIDE = 'R'. */
/* > \endverbatim */
/* > */
/* > \param[in] LDC */
/* > \verbatim */
/* > LDC is INTEGER */
/* > The leading dimension of the array C. LDC >= max(1,M). */
/* > \endverbatim */
/* > */
/* > \param[out] WORK */
/* > \verbatim */
/* > WORK is COMPLEX*16 array, dimension */
/* > (N) if SIDE = 'L' */
/* > or (M) if SIDE = 'R' */
/* > \endverbatim */
/* Authors: */
/* ======== */
/* > \author Univ. of Tennessee */
/* > \author Univ. of California Berkeley */
/* > \author Univ. of Colorado Denver */
/* > \author NAG Ltd. */
/* > \ingroup complex16OTHERauxiliary */
/* ===================================================================== */
/* Subroutine */ int zlarf_(char *side, integer *m, integer *n, doublecomplex
*v, integer *incv, doublecomplex *tau, doublecomplex *c__, integer *
ldc, doublecomplex *work, ftnlen side_len)
{
/* System generated locals */
integer c_dim1, c_offset, i__1;
doublecomplex z__1;
/* Local variables */
integer i__;
logical applyleft;
extern logical lsame_(char *, char *, ftnlen, ftnlen);
integer lastc;
extern /* Subroutine */ int zgerc_(integer *, integer *, doublecomplex *,
doublecomplex *, integer *, doublecomplex *, integer *,
doublecomplex *, integer *), zgemv_(char *, integer *, integer *,
doublecomplex *, doublecomplex *, integer *, doublecomplex *,
integer *, doublecomplex *, doublecomplex *, integer *, ftnlen);
integer lastv;
extern integer ilazlc_(integer *, integer *, doublecomplex *, integer *),
ilazlr_(integer *, integer *, doublecomplex *, integer *);
/* -- LAPACK auxiliary routine -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--v;
c_dim1 = *ldc;
c_offset = 1 + c_dim1;
c__ -= c_offset;
--work;
/* Function Body */
applyleft = lsame_(side, (char *)"L", (ftnlen)1, (ftnlen)1);
lastv = 0;
lastc = 0;
if (tau->r != 0. || tau->i != 0.) {
/* Set up variables for scanning V. LASTV begins pointing to the end */
/* of V. */
if (applyleft) {
lastv = *m;
} else {
lastv = *n;
}
if (*incv > 0) {
i__ = (lastv - 1) * *incv + 1;
} else {
i__ = 1;
}
/* Look for the last non-zero row in V. */
for(;;) { /* while(complicated condition) */
i__1 = i__;
if (!(lastv > 0 && (v[i__1].r == 0. && v[i__1].i == 0.)))
break;
--lastv;
i__ -= *incv;
}
if (applyleft) {
/* Scan for the last non-zero column in C(1:lastv,:). */
lastc = ilazlc_(&lastv, n, &c__[c_offset], ldc);
} else {
/* Scan for the last non-zero row in C(:,1:lastv). */
lastc = ilazlr_(m, &lastv, &c__[c_offset], ldc);
}
}
/* Note that lastc.eq.0 renders the BLAS operations null; no special */
/* case is needed at this level. */
if (applyleft) {
/* Form H * C */
if (lastv > 0) {
/* w(1:lastc,1) := C(1:lastv,1:lastc)**H * v(1:lastv,1) */
zgemv_((char *)"Conjugate transpose", &lastv, &lastc, &c_b1, &c__[
c_offset], ldc, &v[1], incv, &c_b2, &work[1], &c__1, (
ftnlen)19);
/* C(1:lastv,1:lastc) := C(...) - v(1:lastv,1) * w(1:lastc,1)**H */
z__1.r = -tau->r, z__1.i = -tau->i;
zgerc_(&lastv, &lastc, &z__1, &v[1], incv, &work[1], &c__1, &c__[
c_offset], ldc);
}
} else {
/* Form C * H */
if (lastv > 0) {
/* w(1:lastc,1) := C(1:lastc,1:lastv) * v(1:lastv,1) */
zgemv_((char *)"No transpose", &lastc, &lastv, &c_b1, &c__[c_offset], ldc,
&v[1], incv, &c_b2, &work[1], &c__1, (ftnlen)12);
/* C(1:lastc,1:lastv) := C(...) - w(1:lastc,1) * v(1:lastv,1)**H */
z__1.r = -tau->r, z__1.i = -tau->i;
zgerc_(&lastc, &lastv, &z__1, &work[1], &c__1, &v[1], incv, &c__[
c_offset], ldc);
}
}
return 0;
/* End of ZLARF */
} /* zlarf_ */
#ifdef __cplusplus
}
#endif
Reference in New Issue View Git Blame Copy Permalink