256 lines
6.7 KiB
C++
256 lines
6.7 KiB
C++
/* fortran/dorg2r.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 integer c__1 = 1;
|
|
|
|
/* > \brief \b DORG2R generates all or part of the orthogonal matrix Q from a QR factorization determined by s
|
|
geqrf (unblocked algorithm). */
|
|
|
|
/* =========== DOCUMENTATION =========== */
|
|
|
|
/* Online html documentation available at */
|
|
/* http://www.netlib.org/lapack/explore-html/ */
|
|
|
|
/* > \htmlonly */
|
|
/* > Download DORG2R + dependencies */
|
|
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dorg2r.
|
|
f"> */
|
|
/* > [TGZ]</a> */
|
|
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dorg2r.
|
|
f"> */
|
|
/* > [ZIP]</a> */
|
|
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dorg2r.
|
|
f"> */
|
|
/* > [TXT]</a> */
|
|
/* > \endhtmlonly */
|
|
|
|
/* Definition: */
|
|
/* =========== */
|
|
|
|
/* SUBROUTINE DORG2R( M, N, K, A, LDA, TAU, WORK, INFO ) */
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* INTEGER INFO, K, LDA, M, N */
|
|
/* .. */
|
|
/* .. Array Arguments .. */
|
|
/* DOUBLE PRECISION A( LDA, * ), TAU( * ), WORK( * ) */
|
|
/* .. */
|
|
|
|
|
|
/* > \par Purpose: */
|
|
/* ============= */
|
|
/* > */
|
|
/* > \verbatim */
|
|
/* > */
|
|
/* > DORG2R generates an m by n real matrix Q with orthonormal columns, */
|
|
/* > which is defined as the first n columns of a product of k elementary */
|
|
/* > reflectors of order m */
|
|
/* > */
|
|
/* > Q = H(1) H(2) . . . H(k) */
|
|
/* > */
|
|
/* > as returned by DGEQRF. */
|
|
/* > \endverbatim */
|
|
|
|
/* Arguments: */
|
|
/* ========== */
|
|
|
|
/* > \param[in] M */
|
|
/* > \verbatim */
|
|
/* > M is INTEGER */
|
|
/* > The number of rows of the matrix Q. M >= 0. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] N */
|
|
/* > \verbatim */
|
|
/* > N is INTEGER */
|
|
/* > The number of columns of the matrix Q. M >= N >= 0. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] K */
|
|
/* > \verbatim */
|
|
/* > K is INTEGER */
|
|
/* > The number of elementary reflectors whose product defines the */
|
|
/* > matrix Q. N >= K >= 0. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in,out] A */
|
|
/* > \verbatim */
|
|
/* > A is DOUBLE PRECISION array, dimension (LDA,N) */
|
|
/* > On entry, the i-th column must contain the vector which */
|
|
/* > defines the elementary reflector H(i), for i = 1,2,...,k, as */
|
|
/* > returned by DGEQRF in the first k columns of its array */
|
|
/* > argument A. */
|
|
/* > On exit, the m-by-n matrix Q. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] LDA */
|
|
/* > \verbatim */
|
|
/* > LDA is INTEGER */
|
|
/* > The first dimension of the array A. LDA >= max(1,M). */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[in] TAU */
|
|
/* > \verbatim */
|
|
/* > TAU is DOUBLE PRECISION array, dimension (K) */
|
|
/* > TAU(i) must contain the scalar factor of the elementary */
|
|
/* > reflector H(i), as returned by DGEQRF. */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[out] WORK */
|
|
/* > \verbatim */
|
|
/* > WORK is DOUBLE PRECISION array, dimension (N) */
|
|
/* > \endverbatim */
|
|
/* > */
|
|
/* > \param[out] INFO */
|
|
/* > \verbatim */
|
|
/* > INFO is INTEGER */
|
|
/* > = 0: successful exit */
|
|
/* > < 0: if INFO = -i, the i-th argument has an illegal value */
|
|
/* > \endverbatim */
|
|
|
|
/* Authors: */
|
|
/* ======== */
|
|
|
|
/* > \author Univ. of Tennessee */
|
|
/* > \author Univ. of California Berkeley */
|
|
/* > \author Univ. of Colorado Denver */
|
|
/* > \author NAG Ltd. */
|
|
|
|
/* > \ingroup doubleOTHERcomputational */
|
|
|
|
/* ===================================================================== */
|
|
/* Subroutine */ int dorg2r_(integer *m, integer *n, integer *k, doublereal *
|
|
a, integer *lda, doublereal *tau, doublereal *work, integer *info)
|
|
{
|
|
/* System generated locals */
|
|
integer a_dim1, a_offset, i__1, i__2;
|
|
doublereal d__1;
|
|
|
|
/* Local variables */
|
|
integer i__, j, l;
|
|
extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *,
|
|
integer *), dlarf_(char *, integer *, integer *, doublereal *,
|
|
integer *, doublereal *, doublereal *, integer *, doublereal *,
|
|
ftnlen), xerbla_(char *, integer *, ftnlen);
|
|
|
|
|
|
/* -- LAPACK computational 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 .. */
|
|
/* .. */
|
|
/* .. Intrinsic Functions .. */
|
|
/* .. */
|
|
/* .. Executable Statements .. */
|
|
|
|
/* Test the input arguments */
|
|
|
|
/* Parameter adjustments */
|
|
a_dim1 = *lda;
|
|
a_offset = 1 + a_dim1;
|
|
a -= a_offset;
|
|
--tau;
|
|
--work;
|
|
|
|
/* Function Body */
|
|
*info = 0;
|
|
if (*m < 0) {
|
|
*info = -1;
|
|
} else if (*n < 0 || *n > *m) {
|
|
*info = -2;
|
|
} else if (*k < 0 || *k > *n) {
|
|
*info = -3;
|
|
} else if (*lda < max(1,*m)) {
|
|
*info = -5;
|
|
}
|
|
if (*info != 0) {
|
|
i__1 = -(*info);
|
|
xerbla_((char *)"DORG2R", &i__1, (ftnlen)6);
|
|
return 0;
|
|
}
|
|
|
|
/* Quick return if possible */
|
|
|
|
if (*n <= 0) {
|
|
return 0;
|
|
}
|
|
|
|
/* Initialise columns k+1:n to columns of the unit matrix */
|
|
|
|
i__1 = *n;
|
|
for (j = *k + 1; j <= i__1; ++j) {
|
|
i__2 = *m;
|
|
for (l = 1; l <= i__2; ++l) {
|
|
a[l + j * a_dim1] = 0.;
|
|
/* L10: */
|
|
}
|
|
a[j + j * a_dim1] = 1.;
|
|
/* L20: */
|
|
}
|
|
|
|
for (i__ = *k; i__ >= 1; --i__) {
|
|
|
|
/* Apply H(i) to A(i:m,i:n) from the left */
|
|
|
|
if (i__ < *n) {
|
|
a[i__ + i__ * a_dim1] = 1.;
|
|
i__1 = *m - i__ + 1;
|
|
i__2 = *n - i__;
|
|
dlarf_((char *)"Left", &i__1, &i__2, &a[i__ + i__ * a_dim1], &c__1, &tau[
|
|
i__], &a[i__ + (i__ + 1) * a_dim1], lda, &work[1], (
|
|
ftnlen)4);
|
|
}
|
|
if (i__ < *m) {
|
|
i__1 = *m - i__;
|
|
d__1 = -tau[i__];
|
|
dscal_(&i__1, &d__1, &a[i__ + 1 + i__ * a_dim1], &c__1);
|
|
}
|
|
a[i__ + i__ * a_dim1] = 1. - tau[i__];
|
|
|
|
/* Set A(1:i-1,i) to zero */
|
|
|
|
i__1 = i__ - 1;
|
|
for (l = 1; l <= i__1; ++l) {
|
|
a[l + i__ * a_dim1] = 0.;
|
|
/* L30: */
|
|
}
|
|
/* L40: */
|
|
}
|
|
return 0;
|
|
|
|
/* End of DORG2R */
|
|
|
|
} /* dorg2r_ */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|