Add graph references
This commit is contained in:
Abdelrahman Said
+244
@@ -0,0 +1,244 @@
|
||||
/* -- translated by f2c (version 20240504).
|
||||
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 "f2c.h"
|
||||
|
||||
/* Table of constant values */
|
||||
|
||||
static integer c__1 = 1;
|
||||
static doublereal c_b8 = -1.;
|
||||
|
||||
/* > \brief \b DGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row
|
||||
interchanges (unblocked algorithm).
|
||||
|
||||
=========== DOCUMENTATION ===========
|
||||
|
||||
Online html documentation available at
|
||||
http://www.netlib.org/lapack/explore-html/
|
||||
|
||||
> \htmlonly
|
||||
> Download DGETF2 + dependencies
|
||||
> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dgetf2.
|
||||
f">
|
||||
> [TGZ]</a>
|
||||
> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dgetf2.
|
||||
f">
|
||||
> [ZIP]</a>
|
||||
> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dgetf2.
|
||||
f">
|
||||
> [TXT]</a>
|
||||
> \endhtmlonly
|
||||
|
||||
Definition:
|
||||
===========
|
||||
|
||||
SUBROUTINE DGETF2( M, N, A, LDA, IPIV, INFO )
|
||||
|
||||
INTEGER INFO, LDA, M, N
|
||||
INTEGER IPIV( * )
|
||||
DOUBLE PRECISION A( LDA, * )
|
||||
|
||||
|
||||
> \par Purpose:
|
||||
=============
|
||||
>
|
||||
> \verbatim
|
||||
>
|
||||
> DGETF2 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 2 BLAS version of the algorithm.
|
||||
> \endverbatim
|
||||
|
||||
Arguments:
|
||||
==========
|
||||
|
||||
> \param[in] M
|
||||
> \verbatim
|
||||
> M is INTEGER
|
||||
> The number of rows of the matrix A. M >= 0.
|
||||
> \endverbatim
|
||||
>
|
||||
> \param[in] N
|
||||
> \verbatim
|
||||
> N is INTEGER
|
||||
> The number of columns of the matrix A. N >= 0.
|
||||
> \endverbatim
|
||||
>
|
||||
> \param[in,out] A
|
||||
> \verbatim
|
||||
> A is 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.
|
||||
> \endverbatim
|
||||
>
|
||||
> \param[in] LDA
|
||||
> \verbatim
|
||||
> LDA is INTEGER
|
||||
> The leading dimension of the array A. LDA >= max(1,M).
|
||||
> \endverbatim
|
||||
>
|
||||
> \param[out] IPIV
|
||||
> \verbatim
|
||||
> IPIV is 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).
|
||||
> \endverbatim
|
||||
>
|
||||
> \param[out] INFO
|
||||
> \verbatim
|
||||
> INFO is INTEGER
|
||||
> = 0: successful exit
|
||||
> < 0: if INFO = -k, the k-th argument had an illegal value
|
||||
> > 0: if INFO = k, U(k,k) 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.
|
||||
> \endverbatim
|
||||
|
||||
Authors:
|
||||
========
|
||||
|
||||
> \author Univ. of Tennessee
|
||||
> \author Univ. of California Berkeley
|
||||
> \author Univ. of Colorado Denver
|
||||
> \author NAG Ltd.
|
||||
|
||||
> \date September 2012
|
||||
|
||||
> \ingroup doubleGEcomputational
|
||||
|
||||
=====================================================================
|
||||
Subroutine */ int igraphdgetf2_(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;
|
||||
doublereal d__1;
|
||||
|
||||
/* Local variables */
|
||||
integer i__, j, jp;
|
||||
extern /* Subroutine */ int igraphdger_(integer *, integer *, doublereal *,
|
||||
doublereal *, integer *, doublereal *, integer *, doublereal *,
|
||||
integer *), igraphdscal_(integer *, doublereal *, doublereal *, integer
|
||||
*);
|
||||
doublereal sfmin;
|
||||
extern /* Subroutine */ int igraphdswap_(integer *, doublereal *, integer *,
|
||||
doublereal *, integer *);
|
||||
extern doublereal igraphdlamch_(char *);
|
||||
extern integer igraphidamax_(integer *, doublereal *, integer *);
|
||||
extern /* Subroutine */ int igraphxerbla_(char *, integer *, ftnlen);
|
||||
|
||||
|
||||
/* -- LAPACK computational routine (version 3.4.2) --
|
||||
-- LAPACK is a software package provided by Univ. of Tennessee, --
|
||||
-- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
|
||||
September 2012
|
||||
|
||||
|
||||
=====================================================================
|
||||
|
||||
|
||||
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);
|
||||
igraphxerbla_("DGETF2", &i__1, (ftnlen)6);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Quick return if possible */
|
||||
|
||||
if (*m == 0 || *n == 0) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Compute machine safe minimum */
|
||||
|
||||
sfmin = igraphdlamch_("S");
|
||||
|
||||
i__1 = min(*m,*n);
|
||||
for (j = 1; j <= i__1; ++j) {
|
||||
|
||||
/* Find pivot and test for singularity. */
|
||||
|
||||
i__2 = *m - j + 1;
|
||||
jp = j - 1 + igraphidamax_(&i__2, &a[j + j * a_dim1], &c__1);
|
||||
ipiv[j] = jp;
|
||||
if (a[jp + j * a_dim1] != 0.) {
|
||||
|
||||
/* Apply the interchange to columns 1:N. */
|
||||
|
||||
if (jp != j) {
|
||||
igraphdswap_(n, &a[j + a_dim1], lda, &a[jp + a_dim1], lda);
|
||||
}
|
||||
|
||||
/* Compute elements J+1:M of J-th column. */
|
||||
|
||||
if (j < *m) {
|
||||
if ((d__1 = a[j + j * a_dim1], abs(d__1)) >= sfmin) {
|
||||
i__2 = *m - j;
|
||||
d__1 = 1. / a[j + j * a_dim1];
|
||||
igraphdscal_(&i__2, &d__1, &a[j + 1 + j * a_dim1], &c__1);
|
||||
} else {
|
||||
i__2 = *m - j;
|
||||
for (i__ = 1; i__ <= i__2; ++i__) {
|
||||
a[j + i__ + j * a_dim1] /= a[j + j * a_dim1];
|
||||
/* L20: */
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
} else if (*info == 0) {
|
||||
|
||||
*info = j;
|
||||
}
|
||||
|
||||
if (j < min(*m,*n)) {
|
||||
|
||||
/* Update trailing submatrix. */
|
||||
|
||||
i__2 = *m - j;
|
||||
i__3 = *n - j;
|
||||
igraphdger_(&i__2, &i__3, &c_b8, &a[j + 1 + j * a_dim1], &c__1, &a[j + (
|
||||
j + 1) * a_dim1], lda, &a[j + 1 + (j + 1) * a_dim1], lda);
|
||||
}
|
||||
/* L10: */
|
||||
}
|
||||
return 0;
|
||||
|
||||
/* End of DGETF2 */
|
||||
|
||||
} /* igraphdgetf2_ */
|
||||
|
||||
Reference in New Issue
Block a user