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

466 lines
17 KiB
C++

/* static/zlarft.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 integer c__1 = 1;
/* > \brief \b ZLARFT forms the triangular factor T of a block reflector H = I - vtvH */
/* =========== DOCUMENTATION =========== */
/* Online html documentation available at */
/* http://www.netlib.org/lapack/explore-html/ */
/* > \htmlonly */
/* > Download ZLARFT + dependencies */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zlarft.
f"> */
/* > [TGZ]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zlarft.
f"> */
/* > [ZIP]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zlarft.
f"> */
/* > [TXT]</a> */
/* > \endhtmlonly */
/* Definition: */
/* =========== */
/* SUBROUTINE ZLARFT( DIRECT, STOREV, N, K, V, LDV, TAU, T, LDT ) */
/* .. Scalar Arguments .. */
/* CHARACTER DIRECT, STOREV */
/* INTEGER K, LDT, LDV, N */
/* .. */
/* .. Array Arguments .. */
/* COMPLEX*16 T( LDT, * ), TAU( * ), V( LDV, * ) */
/* .. */
/* > \par Purpose: */
/* ============= */
/* > */
/* > \verbatim */
/* > */
/* > ZLARFT forms the triangular factor T of a complex block reflector H */
/* > of order n, which is defined as a product of k elementary reflectors. */
/* > */
/* > If DIRECT = 'F', H = H(1) H(2) . . . H(k) and T is upper triangular; */
/* > */
/* > If DIRECT = 'B', H = H(k) . . . H(2) H(1) and T is lower triangular. */
/* > */
/* > If STOREV = 'C', the vector which defines the elementary reflector */
/* > H(i) is stored in the i-th column of the array V, and */
/* > */
/* > H = I - V * T * V**H */
/* > */
/* > If STOREV = 'R', the vector which defines the elementary reflector */
/* > H(i) is stored in the i-th row of the array V, and */
/* > */
/* > H = I - V**H * T * V */
/* > \endverbatim */
/* Arguments: */
/* ========== */
/* > \param[in] DIRECT */
/* > \verbatim */
/* > DIRECT is CHARACTER*1 */
/* > Specifies the order in which the elementary reflectors are */
/* > multiplied to form the block reflector: */
/* > = 'F': H = H(1) H(2) . . . H(k) (Forward) */
/* > = 'B': H = H(k) . . . H(2) H(1) (Backward) */
/* > \endverbatim */
/* > */
/* > \param[in] STOREV */
/* > \verbatim */
/* > STOREV is CHARACTER*1 */
/* > Specifies how the vectors which define the elementary */
/* > reflectors are stored (see also Further Details): */
/* > = 'C': columnwise */
/* > = 'R': rowwise */
/* > \endverbatim */
/* > */
/* > \param[in] N */
/* > \verbatim */
/* > N is INTEGER */
/* > The order of the block reflector H. N >= 0. */
/* > \endverbatim */
/* > */
/* > \param[in] K */
/* > \verbatim */
/* > K is INTEGER */
/* > The order of the triangular factor T (= the number of */
/* > elementary reflectors). K >= 1. */
/* > \endverbatim */
/* > */
/* > \param[in] V */
/* > \verbatim */
/* > V is COMPLEX*16 array, dimension */
/* > (LDV,K) if STOREV = 'C' */
/* > (LDV,N) if STOREV = 'R' */
/* > The matrix V. See further details. */
/* > \endverbatim */
/* > */
/* > \param[in] LDV */
/* > \verbatim */
/* > LDV is INTEGER */
/* > The leading dimension of the array V. */
/* > If STOREV = 'C', LDV >= max(1,N); if STOREV = 'R', LDV >= K. */
/* > \endverbatim */
/* > */
/* > \param[in] TAU */
/* > \verbatim */
/* > TAU is COMPLEX*16 array, dimension (K) */
/* > TAU(i) must contain the scalar factor of the elementary */
/* > reflector H(i). */
/* > \endverbatim */
/* > */
/* > \param[out] T */
/* > \verbatim */
/* > T is COMPLEX*16 array, dimension (LDT,K) */
/* > The k by k triangular factor T of the block reflector. */
/* > If DIRECT = 'F', T is upper triangular; if DIRECT = 'B', T is */
/* > lower triangular. The rest of the array is not used. */
/* > \endverbatim */
/* > */
/* > \param[in] LDT */
/* > \verbatim */
/* > LDT is INTEGER */
/* > The leading dimension of the array T. LDT >= K. */
/* > \endverbatim */
/* Authors: */
/* ======== */
/* > \author Univ. of Tennessee */
/* > \author Univ. of California Berkeley */
/* > \author Univ. of Colorado Denver */
/* > \author NAG Ltd. */
/* > \ingroup complex16OTHERauxiliary */
/* > \par Further Details: */
/* ===================== */
/* > */
/* > \verbatim */
/* > */
/* > The shape of the matrix V and the storage of the vectors which define */
/* > the H(i) is best illustrated by the following example with n = 5 and */
/* > k = 3. The elements equal to 1 are not stored. */
/* > */
/* > DIRECT = 'F' and STOREV = 'C': DIRECT = 'F' and STOREV = 'R': */
/* > */
/* > V = ( 1 ) V = ( 1 v1 v1 v1 v1 ) */
/* > ( v1 1 ) ( 1 v2 v2 v2 ) */
/* > ( v1 v2 1 ) ( 1 v3 v3 ) */
/* > ( v1 v2 v3 ) */
/* > ( v1 v2 v3 ) */
/* > */
/* > DIRECT = 'B' and STOREV = 'C': DIRECT = 'B' and STOREV = 'R': */
/* > */
/* > V = ( v1 v2 v3 ) V = ( v1 v1 1 ) */
/* > ( v1 v2 v3 ) ( v2 v2 v2 1 ) */
/* > ( 1 v2 v3 ) ( v3 v3 v3 v3 1 ) */
/* > ( 1 v3 ) */
/* > ( 1 ) */
/* > \endverbatim */
/* > */
/* ===================================================================== */
/* Subroutine */ int zlarft_(char *direct, char *storev, integer *n, integer *
k, doublecomplex *v, integer *ldv, doublecomplex *tau, doublecomplex *
t, integer *ldt, ftnlen direct_len, ftnlen storev_len)
{
/* System generated locals */
integer t_dim1, t_offset, v_dim1, v_offset, i__1, i__2, i__3, i__4, i__5;
doublecomplex z__1, z__2, z__3;
/* Builtin functions */
void d_cnjg(doublecomplex *, doublecomplex *);
/* Local variables */
integer i__, j, prevlastv;
extern logical lsame_(char *, char *, ftnlen, ftnlen);
extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *,
integer *, doublecomplex *, doublecomplex *, integer *,
doublecomplex *, integer *, doublecomplex *, doublecomplex *,
integer *, ftnlen, ftnlen), zgemv_(char *, integer *, integer *,
doublecomplex *, doublecomplex *, integer *, doublecomplex *,
integer *, doublecomplex *, doublecomplex *, integer *, ftnlen);
integer lastv;
extern /* Subroutine */ int ztrmv_(char *, char *, char *, integer *,
doublecomplex *, integer *, doublecomplex *, integer *, ftnlen,
ftnlen, ftnlen);
/* -- 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 .. */
/* Quick return if possible */
/* Parameter adjustments */
v_dim1 = *ldv;
v_offset = 1 + v_dim1;
v -= v_offset;
--tau;
t_dim1 = *ldt;
t_offset = 1 + t_dim1;
t -= t_offset;
/* Function Body */
if (*n == 0) {
return 0;
}
if (lsame_(direct, (char *)"F", (ftnlen)1, (ftnlen)1)) {
prevlastv = *n;
i__1 = *k;
for (i__ = 1; i__ <= i__1; ++i__) {
prevlastv = max(prevlastv,i__);
i__2 = i__;
if (tau[i__2].r == 0. && tau[i__2].i == 0.) {
/* H(i) = I */
i__2 = i__;
for (j = 1; j <= i__2; ++j) {
i__3 = j + i__ * t_dim1;
t[i__3].r = 0., t[i__3].i = 0.;
}
} else {
/* general case */
if (lsame_(storev, (char *)"C", (ftnlen)1, (ftnlen)1)) {
/* Skip any trailing zeros. */
i__2 = i__ + 1;
for (lastv = *n; lastv >= i__2; --lastv) {
i__3 = lastv + i__ * v_dim1;
if (v[i__3].r != 0. || v[i__3].i != 0.) {
goto L220;
}
}
L220:
i__2 = i__ - 1;
for (j = 1; j <= i__2; ++j) {
i__3 = j + i__ * t_dim1;
i__4 = i__;
z__2.r = -tau[i__4].r, z__2.i = -tau[i__4].i;
d_cnjg(&z__3, &v[i__ + j * v_dim1]);
z__1.r = z__2.r * z__3.r - z__2.i * z__3.i, z__1.i =
z__2.r * z__3.i + z__2.i * z__3.r;
t[i__3].r = z__1.r, t[i__3].i = z__1.i;
}
j = min(lastv,prevlastv);
/* T(1:i-1,i) := - tau(i) * V(i:j,1:i-1)**H * V(i:j,i) */
i__2 = j - i__;
i__3 = i__ - 1;
i__4 = i__;
z__1.r = -tau[i__4].r, z__1.i = -tau[i__4].i;
zgemv_((char *)"Conjugate transpose", &i__2, &i__3, &z__1, &v[i__
+ 1 + v_dim1], ldv, &v[i__ + 1 + i__ * v_dim1], &
c__1, &c_b1, &t[i__ * t_dim1 + 1], &c__1, (ftnlen)
19);
} else {
/* Skip any trailing zeros. */
i__2 = i__ + 1;
for (lastv = *n; lastv >= i__2; --lastv) {
i__3 = i__ + lastv * v_dim1;
if (v[i__3].r != 0. || v[i__3].i != 0.) {
goto L236;
}
}
L236:
i__2 = i__ - 1;
for (j = 1; j <= i__2; ++j) {
i__3 = j + i__ * t_dim1;
i__4 = i__;
z__2.r = -tau[i__4].r, z__2.i = -tau[i__4].i;
i__5 = j + i__ * v_dim1;
z__1.r = z__2.r * v[i__5].r - z__2.i * v[i__5].i,
z__1.i = z__2.r * v[i__5].i + z__2.i * v[i__5]
.r;
t[i__3].r = z__1.r, t[i__3].i = z__1.i;
}
j = min(lastv,prevlastv);
/* T(1:i-1,i) := - tau(i) * V(1:i-1,i:j) * V(i,i:j)**H */
i__2 = i__ - 1;
i__3 = j - i__;
i__4 = i__;
z__1.r = -tau[i__4].r, z__1.i = -tau[i__4].i;
zgemm_((char *)"N", (char *)"C", &i__2, &c__1, &i__3, &z__1, &v[(i__ + 1)
* v_dim1 + 1], ldv, &v[i__ + (i__ + 1) * v_dim1],
ldv, &c_b1, &t[i__ * t_dim1 + 1], ldt, (ftnlen)1,
(ftnlen)1);
}
/* T(1:i-1,i) := T(1:i-1,1:i-1) * T(1:i-1,i) */
i__2 = i__ - 1;
ztrmv_((char *)"Upper", (char *)"No transpose", (char *)"Non-unit", &i__2, &t[
t_offset], ldt, &t[i__ * t_dim1 + 1], &c__1, (ftnlen)
5, (ftnlen)12, (ftnlen)8);
i__2 = i__ + i__ * t_dim1;
i__3 = i__;
t[i__2].r = tau[i__3].r, t[i__2].i = tau[i__3].i;
if (i__ > 1) {
prevlastv = max(prevlastv,lastv);
} else {
prevlastv = lastv;
}
}
}
} else {
prevlastv = 1;
for (i__ = *k; i__ >= 1; --i__) {
i__1 = i__;
if (tau[i__1].r == 0. && tau[i__1].i == 0.) {
/* H(i) = I */
i__1 = *k;
for (j = i__; j <= i__1; ++j) {
i__2 = j + i__ * t_dim1;
t[i__2].r = 0., t[i__2].i = 0.;
}
} else {
/* general case */
if (i__ < *k) {
if (lsame_(storev, (char *)"C", (ftnlen)1, (ftnlen)1)) {
/* Skip any leading zeros. */
i__1 = i__ - 1;
for (lastv = 1; lastv <= i__1; ++lastv) {
i__2 = lastv + i__ * v_dim1;
if (v[i__2].r != 0. || v[i__2].i != 0.) {
goto L281;
}
}
L281:
i__1 = *k;
for (j = i__ + 1; j <= i__1; ++j) {
i__2 = j + i__ * t_dim1;
i__3 = i__;
z__2.r = -tau[i__3].r, z__2.i = -tau[i__3].i;
d_cnjg(&z__3, &v[*n - *k + i__ + j * v_dim1]);
z__1.r = z__2.r * z__3.r - z__2.i * z__3.i,
z__1.i = z__2.r * z__3.i + z__2.i *
z__3.r;
t[i__2].r = z__1.r, t[i__2].i = z__1.i;
}
j = max(lastv,prevlastv);
/* T(i+1:k,i) = -tau(i) * V(j:n-k+i,i+1:k)**H * V(j:n-k+i,i) */
i__1 = *n - *k + i__ - j;
i__2 = *k - i__;
i__3 = i__;
z__1.r = -tau[i__3].r, z__1.i = -tau[i__3].i;
zgemv_((char *)"Conjugate transpose", &i__1, &i__2, &z__1, &v[
j + (i__ + 1) * v_dim1], ldv, &v[j + i__ *
v_dim1], &c__1, &c_b1, &t[i__ + 1 + i__ *
t_dim1], &c__1, (ftnlen)19);
} else {
/* Skip any leading zeros. */
i__1 = i__ - 1;
for (lastv = 1; lastv <= i__1; ++lastv) {
i__2 = i__ + lastv * v_dim1;
if (v[i__2].r != 0. || v[i__2].i != 0.) {
goto L297;
}
}
L297:
i__1 = *k;
for (j = i__ + 1; j <= i__1; ++j) {
i__2 = j + i__ * t_dim1;
i__3 = i__;
z__2.r = -tau[i__3].r, z__2.i = -tau[i__3].i;
i__4 = j + (*n - *k + i__) * v_dim1;
z__1.r = z__2.r * v[i__4].r - z__2.i * v[i__4].i,
z__1.i = z__2.r * v[i__4].i + z__2.i * v[
i__4].r;
t[i__2].r = z__1.r, t[i__2].i = z__1.i;
}
j = max(lastv,prevlastv);
/* T(i+1:k,i) = -tau(i) * V(i+1:k,j:n-k+i) * V(i,j:n-k+i)**H */
i__1 = *k - i__;
i__2 = *n - *k + i__ - j;
i__3 = i__;
z__1.r = -tau[i__3].r, z__1.i = -tau[i__3].i;
zgemm_((char *)"N", (char *)"C", &i__1, &c__1, &i__2, &z__1, &v[i__ +
1 + j * v_dim1], ldv, &v[i__ + j * v_dim1],
ldv, &c_b1, &t[i__ + 1 + i__ * t_dim1], ldt, (
ftnlen)1, (ftnlen)1);
}
/* T(i+1:k,i) := T(i+1:k,i+1:k) * T(i+1:k,i) */
i__1 = *k - i__;
ztrmv_((char *)"Lower", (char *)"No transpose", (char *)"Non-unit", &i__1, &t[i__
+ 1 + (i__ + 1) * t_dim1], ldt, &t[i__ + 1 + i__ *
t_dim1], &c__1, (ftnlen)5, (ftnlen)12, (ftnlen)8)
;
if (i__ > 1) {
prevlastv = min(prevlastv,lastv);
} else {
prevlastv = lastv;
}
}
i__1 = i__ + i__ * t_dim1;
i__2 = i__;
t[i__1].r = tau[i__2].r, t[i__1].i = tau[i__2].i;
}
}
}
return 0;
/* End of ZLARFT */
} /* zlarft_ */
#ifdef __cplusplus
}
#endif