220 lines
6.2 KiB
C
220 lines
6.2 KiB
C
/* dgetrf.f -- translated by f2c (version 20061008).
|
|
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
|
|
*/
|
|
|
|
#include "clapack.h"
|
|
|
|
|
|
/* Table of constant values */
|
|
|
|
static integer c__1 = 1;
|
|
static integer c_n1 = -1;
|
|
static doublereal c_b16 = 1.;
|
|
static doublereal c_b19 = -1.;
|
|
|
|
/* Subroutine */ int dgetrf_(integer *m, integer *n, doublereal *a, integer *
|
|
lda, integer *ipiv, integer *info)
|
|
{
|
|
/* System generated locals */
|
|
integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5;
|
|
|
|
/* Local variables */
|
|
integer i__, j, jb, nb;
|
|
extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *,
|
|
integer *, doublereal *, doublereal *, integer *, doublereal *,
|
|
integer *, doublereal *, doublereal *, integer *);
|
|
integer iinfo;
|
|
extern /* Subroutine */ int dtrsm_(char *, char *, char *, char *,
|
|
integer *, integer *, doublereal *, doublereal *, integer *,
|
|
doublereal *, integer *), dgetf2_(
|
|
integer *, integer *, doublereal *, integer *, integer *, integer
|
|
*), xerbla_(char *, integer *);
|
|
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
|
|
integer *, integer *);
|
|
extern /* Subroutine */ int dlaswp_(integer *, doublereal *, integer *,
|
|
integer *, integer *, integer *, integer *);
|
|
|
|
|
|
/* -- LAPACK routine (version 3.2) -- */
|
|
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
|
|
/* November 2006 */
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* .. */
|
|
/* .. Array Arguments .. */
|
|
/* .. */
|
|
|
|
/* Purpose */
|
|
/* ======= */
|
|
|
|
/* DGETRF computes an LU factorization of a general M-by-N matrix A */
|
|
/* using partial pivoting with row interchanges. */
|
|
|
|
/* The factorization has the form */
|
|
/* A = P * L * U */
|
|
/* where P is a permutation matrix, L is lower triangular with unit */
|
|
/* diagonal elements (lower trapezoidal if m > n), and U is upper */
|
|
/* triangular (upper trapezoidal if m < n). */
|
|
|
|
/* This is the right-looking Level 3 BLAS version of the algorithm. */
|
|
|
|
/* Arguments */
|
|
/* ========= */
|
|
|
|
/* M (input) INTEGER */
|
|
/* The number of rows of the matrix A. M >= 0. */
|
|
|
|
/* N (input) INTEGER */
|
|
/* The number of columns of the matrix A. N >= 0. */
|
|
|
|
/* A (input/output) DOUBLE PRECISION array, dimension (LDA,N) */
|
|
/* On entry, the M-by-N matrix to be factored. */
|
|
/* On exit, the factors L and U from the factorization */
|
|
/* A = P*L*U; the unit diagonal elements of L are not stored. */
|
|
|
|
/* LDA (input) INTEGER */
|
|
/* The leading dimension of the array A. LDA >= max(1,M). */
|
|
|
|
/* IPIV (output) INTEGER array, dimension (min(M,N)) */
|
|
/* The pivot indices; for 1 <= i <= min(M,N), row i of the */
|
|
/* matrix was interchanged with row IPIV(i). */
|
|
|
|
/* INFO (output) INTEGER */
|
|
/* = 0: successful exit */
|
|
/* < 0: if INFO = -i, the i-th argument had an illegal value */
|
|
/* > 0: if INFO = i, U(i,i) is exactly zero. The factorization */
|
|
/* has been completed, but the factor U is exactly */
|
|
/* singular, and division by zero will occur if it is used */
|
|
/* to solve a system of equations. */
|
|
|
|
/* ===================================================================== */
|
|
|
|
/* .. Parameters .. */
|
|
/* .. */
|
|
/* .. Local Scalars .. */
|
|
/* .. */
|
|
/* .. External Subroutines .. */
|
|
/* .. */
|
|
/* .. External Functions .. */
|
|
/* .. */
|
|
/* .. Intrinsic Functions .. */
|
|
/* .. */
|
|
/* .. Executable Statements .. */
|
|
|
|
/* Test the input parameters. */
|
|
|
|
/* Parameter adjustments */
|
|
a_dim1 = *lda;
|
|
a_offset = 1 + a_dim1;
|
|
a -= a_offset;
|
|
--ipiv;
|
|
|
|
/* Function Body */
|
|
*info = 0;
|
|
if (*m < 0) {
|
|
*info = -1;
|
|
} else if (*n < 0) {
|
|
*info = -2;
|
|
} else if (*lda < max(1,*m)) {
|
|
*info = -4;
|
|
}
|
|
if (*info != 0) {
|
|
i__1 = -(*info);
|
|
xerbla_("DGETRF", &i__1);
|
|
return 0;
|
|
}
|
|
|
|
/* Quick return if possible */
|
|
|
|
if (*m == 0 || *n == 0) {
|
|
return 0;
|
|
}
|
|
|
|
/* Determine the block size for this environment. */
|
|
|
|
nb = ilaenv_(&c__1, "DGETRF", " ", m, n, &c_n1, &c_n1);
|
|
if (nb <= 1 || nb >= min(*m,*n)) {
|
|
|
|
/* Use unblocked code. */
|
|
|
|
dgetf2_(m, n, &a[a_offset], lda, &ipiv[1], info);
|
|
} else {
|
|
|
|
/* Use blocked code. */
|
|
|
|
i__1 = min(*m,*n);
|
|
i__2 = nb;
|
|
for (j = 1; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
|
|
/* Computing MIN */
|
|
i__3 = min(*m,*n) - j + 1;
|
|
jb = min(i__3,nb);
|
|
|
|
/* Factor diagonal and subdiagonal blocks and test for exact */
|
|
/* singularity. */
|
|
|
|
i__3 = *m - j + 1;
|
|
dgetf2_(&i__3, &jb, &a[j + j * a_dim1], lda, &ipiv[j], &iinfo);
|
|
|
|
/* Adjust INFO and the pivot indices. */
|
|
|
|
if (*info == 0 && iinfo > 0) {
|
|
*info = iinfo + j - 1;
|
|
}
|
|
/* Computing MIN */
|
|
i__4 = *m, i__5 = j + jb - 1;
|
|
i__3 = min(i__4,i__5);
|
|
for (i__ = j; i__ <= i__3; ++i__) {
|
|
ipiv[i__] = j - 1 + ipiv[i__];
|
|
/* L10: */
|
|
}
|
|
|
|
/* Apply interchanges to columns 1:J-1. */
|
|
|
|
i__3 = j - 1;
|
|
i__4 = j + jb - 1;
|
|
dlaswp_(&i__3, &a[a_offset], lda, &j, &i__4, &ipiv[1], &c__1);
|
|
|
|
if (j + jb <= *n) {
|
|
|
|
/* Apply interchanges to columns J+JB:N. */
|
|
|
|
i__3 = *n - j - jb + 1;
|
|
i__4 = j + jb - 1;
|
|
dlaswp_(&i__3, &a[(j + jb) * a_dim1 + 1], lda, &j, &i__4, &
|
|
ipiv[1], &c__1);
|
|
|
|
/* Compute block row of U. */
|
|
|
|
i__3 = *n - j - jb + 1;
|
|
dtrsm_("Left", "Lower", "No transpose", "Unit", &jb, &i__3, &
|
|
c_b16, &a[j + j * a_dim1], lda, &a[j + (j + jb) *
|
|
a_dim1], lda);
|
|
if (j + jb <= *m) {
|
|
|
|
/* Update trailing submatrix. */
|
|
|
|
i__3 = *m - j - jb + 1;
|
|
i__4 = *n - j - jb + 1;
|
|
dgemm_("No transpose", "No transpose", &i__3, &i__4, &jb,
|
|
&c_b19, &a[j + jb + j * a_dim1], lda, &a[j + (j +
|
|
jb) * a_dim1], lda, &c_b16, &a[j + jb + (j + jb) *
|
|
a_dim1], lda);
|
|
}
|
|
}
|
|
/* L20: */
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
/* End of DGETRF */
|
|
|
|
} /* dgetrf_ */
|