convert linalg library from Fortran to C++
This commit is contained in:
Axel Kohlmeyer
381
lib/linalg/zungql.cpp
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381
lib/linalg/zungql.cpp
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@ -0,0 +1,381 @@
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/* fortran/zungql.f -- translated by f2c (version 20200916).
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You must link the resulting object file with libf2c:
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on Microsoft Windows system, link with libf2c.lib;
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on Linux or Unix systems, link with .../path/to/libf2c.a -lm
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or, if you install libf2c.a in a standard place, with -lf2c -lm
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-- in that order, at the end of the command line, as in
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cc *.o -lf2c -lm
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Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
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http://www.netlib.org/f2c/libf2c.zip
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include "lmp_f2c.h"
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/* Table of constant values */
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static integer c__1 = 1;
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static integer c_n1 = -1;
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static integer c__3 = 3;
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static integer c__2 = 2;
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/* > \brief \b ZUNGQL */
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/* =========== DOCUMENTATION =========== */
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/* Online html documentation available at */
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/* http://www.netlib.org/lapack/explore-html/ */
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/* > \htmlonly */
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/* > Download ZUNGQL + dependencies */
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/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zungql.
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f"> */
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/* > [TGZ]</a> */
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/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zungql.
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f"> */
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/* > [ZIP]</a> */
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/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zungql.
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f"> */
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/* > [TXT]</a> */
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/* > \endhtmlonly */
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/* Definition: */
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/* =========== */
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/* SUBROUTINE ZUNGQL( M, N, K, A, LDA, TAU, WORK, LWORK, INFO ) */
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/* .. Scalar Arguments .. */
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/* INTEGER INFO, K, LDA, LWORK, M, N */
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/* .. */
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/* .. Array Arguments .. */
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/* COMPLEX*16 A( LDA, * ), TAU( * ), WORK( * ) */
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/* .. */
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/* > \par Purpose: */
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/* ============= */
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/* > */
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/* > \verbatim */
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/* > */
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/* > ZUNGQL generates an M-by-N complex matrix Q with orthonormal columns, */
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/* > which is defined as the last N columns of a product of K elementary */
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/* > reflectors of order M */
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/* > */
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/* > Q = H(k) . . . H(2) H(1) */
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/* > */
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/* > as returned by ZGEQLF. */
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/* > \endverbatim */
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/* Arguments: */
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/* ========== */
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/* > \param[in] M */
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/* > \verbatim */
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/* > M is INTEGER */
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/* > The number of rows of the matrix Q. M >= 0. */
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/* > \endverbatim */
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/* > */
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/* > \param[in] N */
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/* > \verbatim */
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/* > N is INTEGER */
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/* > The number of columns of the matrix Q. M >= N >= 0. */
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/* > \endverbatim */
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/* > */
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/* > \param[in] K */
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/* > \verbatim */
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/* > K is INTEGER */
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/* > The number of elementary reflectors whose product defines the */
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/* > matrix Q. N >= K >= 0. */
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/* > \endverbatim */
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/* > */
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/* > \param[in,out] A */
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/* > \verbatim */
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/* > A is COMPLEX*16 array, dimension (LDA,N) */
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/* > On entry, the (n-k+i)-th column must contain the vector which */
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/* > defines the elementary reflector H(i), for i = 1,2,...,k, as */
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/* > returned by ZGEQLF in the last k columns of its array */
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/* > argument A. */
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/* > On exit, the M-by-N matrix Q. */
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/* > \endverbatim */
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/* > */
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/* > \param[in] LDA */
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/* > \verbatim */
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/* > LDA is INTEGER */
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/* > The first dimension of the array A. LDA >= max(1,M). */
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/* > \endverbatim */
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/* > */
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/* > \param[in] TAU */
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/* > \verbatim */
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/* > TAU is COMPLEX*16 array, dimension (K) */
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/* > TAU(i) must contain the scalar factor of the elementary */
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/* > reflector H(i), as returned by ZGEQLF. */
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/* > \endverbatim */
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/* > */
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/* > \param[out] WORK */
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/* > \verbatim */
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/* > WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)) */
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/* > On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
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/* > \endverbatim */
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/* > */
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/* > \param[in] LWORK */
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/* > \verbatim */
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/* > LWORK is INTEGER */
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/* > The dimension of the array WORK. LWORK >= max(1,N). */
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/* > For optimum performance LWORK >= N*NB, where NB is the */
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/* > optimal blocksize. */
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/* > */
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/* > If LWORK = -1, then a workspace query is assumed; the routine */
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/* > only calculates the optimal size of the WORK array, returns */
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/* > this value as the first entry of the WORK array, and no error */
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/* > message related to LWORK is issued by XERBLA. */
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/* > \endverbatim */
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/* > */
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/* > \param[out] INFO */
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/* > \verbatim */
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/* > INFO is INTEGER */
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/* > = 0: successful exit */
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/* > < 0: if INFO = -i, the i-th argument has an illegal value */
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/* > \endverbatim */
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/* Authors: */
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/* ======== */
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/* > \author Univ. of Tennessee */
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/* > \author Univ. of California Berkeley */
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/* > \author Univ. of Colorado Denver */
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/* > \author NAG Ltd. */
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/* > \ingroup complex16OTHERcomputational */
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/* ===================================================================== */
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/* Subroutine */ int zungql_(integer *m, integer *n, integer *k,
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doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *
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work, integer *lwork, integer *info)
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{
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/* System generated locals */
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integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5;
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/* Local variables */
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integer i__, j, l, ib, nb, kk, nx, iws, nbmin, iinfo;
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extern /* Subroutine */ int zung2l_(integer *, integer *, integer *,
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doublecomplex *, integer *, doublecomplex *, doublecomplex *,
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integer *), xerbla_(char *, integer *, ftnlen);
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extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
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integer *, integer *, ftnlen, ftnlen);
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extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *,
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integer *, integer *, integer *, doublecomplex *, integer *,
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doublecomplex *, integer *, doublecomplex *, integer *,
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doublecomplex *, integer *, ftnlen, ftnlen, ftnlen, ftnlen);
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integer ldwork;
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extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *,
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doublecomplex *, integer *, doublecomplex *, doublecomplex *,
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integer *, ftnlen, ftnlen);
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logical lquery;
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integer lwkopt;
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/* -- LAPACK computational routine -- */
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/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
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/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
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/* .. Scalar Arguments .. */
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/* .. */
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/* .. Array Arguments .. */
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/* .. */
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/* ===================================================================== */
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/* .. Parameters .. */
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/* .. */
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/* .. Local Scalars .. */
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/* .. */
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/* .. External Subroutines .. */
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/* .. */
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/* .. Intrinsic Functions .. */
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/* .. */
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/* .. External Functions .. */
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/* .. */
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/* .. Executable Statements .. */
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/* Test the input arguments */
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/* Parameter adjustments */
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a_dim1 = *lda;
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a_offset = 1 + a_dim1;
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a -= a_offset;
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--tau;
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--work;
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/* Function Body */
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*info = 0;
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lquery = *lwork == -1;
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if (*m < 0) {
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*info = -1;
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} else if (*n < 0 || *n > *m) {
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*info = -2;
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} else if (*k < 0 || *k > *n) {
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*info = -3;
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} else if (*lda < max(1,*m)) {
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*info = -5;
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}
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if (*info == 0) {
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if (*n == 0) {
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lwkopt = 1;
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} else {
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nb = ilaenv_(&c__1, (char *)"ZUNGQL", (char *)" ", m, n, k, &c_n1, (ftnlen)6, (
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ftnlen)1);
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lwkopt = *n * nb;
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}
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work[1].r = (doublereal) lwkopt, work[1].i = 0.;
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if (*lwork < max(1,*n) && ! lquery) {
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*info = -8;
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}
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}
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if (*info != 0) {
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i__1 = -(*info);
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xerbla_((char *)"ZUNGQL", &i__1, (ftnlen)6);
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return 0;
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} else if (lquery) {
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return 0;
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}
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/* Quick return if possible */
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if (*n <= 0) {
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return 0;
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}
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nbmin = 2;
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nx = 0;
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iws = *n;
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if (nb > 1 && nb < *k) {
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/* Determine when to cross over from blocked to unblocked code. */
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/* Computing MAX */
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i__1 = 0, i__2 = ilaenv_(&c__3, (char *)"ZUNGQL", (char *)" ", m, n, k, &c_n1, (
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ftnlen)6, (ftnlen)1);
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nx = max(i__1,i__2);
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if (nx < *k) {
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/* Determine if workspace is large enough for blocked code. */
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ldwork = *n;
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iws = ldwork * nb;
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if (*lwork < iws) {
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/* Not enough workspace to use optimal NB: reduce NB and */
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/* determine the minimum value of NB. */
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nb = *lwork / ldwork;
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/* Computing MAX */
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i__1 = 2, i__2 = ilaenv_(&c__2, (char *)"ZUNGQL", (char *)" ", m, n, k, &c_n1,
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(ftnlen)6, (ftnlen)1);
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nbmin = max(i__1,i__2);
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}
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}
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}
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if (nb >= nbmin && nb < *k && nx < *k) {
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/* Use blocked code after the first block. */
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/* The last kk columns are handled by the block method. */
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/* Computing MIN */
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i__1 = *k, i__2 = (*k - nx + nb - 1) / nb * nb;
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kk = min(i__1,i__2);
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/* Set A(m-kk+1:m,1:n-kk) to zero. */
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i__1 = *n - kk;
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for (j = 1; j <= i__1; ++j) {
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i__2 = *m;
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for (i__ = *m - kk + 1; i__ <= i__2; ++i__) {
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i__3 = i__ + j * a_dim1;
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a[i__3].r = 0., a[i__3].i = 0.;
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/* L10: */
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}
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/* L20: */
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}
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} else {
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kk = 0;
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}
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/* Use unblocked code for the first or only block. */
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i__1 = *m - kk;
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i__2 = *n - kk;
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i__3 = *k - kk;
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zung2l_(&i__1, &i__2, &i__3, &a[a_offset], lda, &tau[1], &work[1], &iinfo)
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;
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if (kk > 0) {
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/* Use blocked code */
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i__1 = *k;
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i__2 = nb;
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for (i__ = *k - kk + 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ +=
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i__2) {
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/* Computing MIN */
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i__3 = nb, i__4 = *k - i__ + 1;
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ib = min(i__3,i__4);
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if (*n - *k + i__ > 1) {
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/* Form the triangular factor of the block reflector */
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/* H = H(i+ib-1) . . . H(i+1) H(i) */
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i__3 = *m - *k + i__ + ib - 1;
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zlarft_((char *)"Backward", (char *)"Columnwise", &i__3, &ib, &a[(*n - *k +
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i__) * a_dim1 + 1], lda, &tau[i__], &work[1], &ldwork,
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(ftnlen)8, (ftnlen)10);
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/* Apply H to A(1:m-k+i+ib-1,1:n-k+i-1) from the left */
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i__3 = *m - *k + i__ + ib - 1;
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i__4 = *n - *k + i__ - 1;
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zlarfb_((char *)"Left", (char *)"No transpose", (char *)"Backward", (char *)"Columnwise", &
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i__3, &i__4, &ib, &a[(*n - *k + i__) * a_dim1 + 1],
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lda, &work[1], &ldwork, &a[a_offset], lda, &work[ib +
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1], &ldwork, (ftnlen)4, (ftnlen)12, (ftnlen)8, (
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ftnlen)10);
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}
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/* Apply H to rows 1:m-k+i+ib-1 of current block */
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i__3 = *m - *k + i__ + ib - 1;
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zung2l_(&i__3, &ib, &ib, &a[(*n - *k + i__) * a_dim1 + 1], lda, &
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tau[i__], &work[1], &iinfo);
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/* Set rows m-k+i+ib:m of current block to zero */
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i__3 = *n - *k + i__ + ib - 1;
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for (j = *n - *k + i__; j <= i__3; ++j) {
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i__4 = *m;
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for (l = *m - *k + i__ + ib; l <= i__4; ++l) {
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i__5 = l + j * a_dim1;
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a[i__5].r = 0., a[i__5].i = 0.;
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/* L30: */
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}
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/* L40: */
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}
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/* L50: */
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}
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}
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work[1].r = (doublereal) iws, work[1].i = 0.;
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return 0;
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/* End of ZUNGQL */
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} /* zungql_ */
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#ifdef __cplusplus
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}
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#endif
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