mirror of
https://github.com/opencv/opencv.git
synced 2024-12-01 23:30:06 +08:00
265 lines
7.3 KiB
C
265 lines
7.3 KiB
C
/* dgetri.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 integer c__2 = 2;
|
|
static doublereal c_b20 = -1.;
|
|
static doublereal c_b22 = 1.;
|
|
|
|
/* Subroutine */ int dgetri_(integer *n, doublereal *a, integer *lda, integer
|
|
*ipiv, doublereal *work, integer *lwork, integer *info)
|
|
{
|
|
/* System generated locals */
|
|
integer a_dim1, a_offset, i__1, i__2, i__3;
|
|
|
|
/* Local variables */
|
|
integer i__, j, jb, nb, jj, jp, nn, iws;
|
|
extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *,
|
|
integer *, doublereal *, doublereal *, integer *, doublereal *,
|
|
integer *, doublereal *, doublereal *, integer *),
|
|
dgemv_(char *, integer *, integer *, doublereal *, doublereal *,
|
|
integer *, doublereal *, integer *, doublereal *, doublereal *,
|
|
integer *);
|
|
integer nbmin;
|
|
extern /* Subroutine */ int dswap_(integer *, doublereal *, integer *,
|
|
doublereal *, integer *), dtrsm_(char *, char *, char *, char *,
|
|
integer *, integer *, doublereal *, doublereal *, integer *,
|
|
doublereal *, integer *), xerbla_(
|
|
char *, integer *);
|
|
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
|
|
integer *, integer *);
|
|
integer ldwork;
|
|
extern /* Subroutine */ int dtrtri_(char *, char *, integer *, doublereal
|
|
*, integer *, integer *);
|
|
integer lwkopt;
|
|
logical lquery;
|
|
|
|
|
|
/* -- LAPACK routine (version 3.2) -- */
|
|
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
|
|
/* November 2006 */
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* .. */
|
|
/* .. Array Arguments .. */
|
|
/* .. */
|
|
|
|
/* Purpose */
|
|
/* ======= */
|
|
|
|
/* DGETRI computes the inverse of a matrix using the LU factorization */
|
|
/* computed by DGETRF. */
|
|
|
|
/* This method inverts U and then computes inv(A) by solving the system */
|
|
/* inv(A)*L = inv(U) for inv(A). */
|
|
|
|
/* Arguments */
|
|
/* ========= */
|
|
|
|
/* N (input) INTEGER */
|
|
/* The order of the matrix A. N >= 0. */
|
|
|
|
/* A (input/output) DOUBLE PRECISION array, dimension (LDA,N) */
|
|
/* On entry, the factors L and U from the factorization */
|
|
/* A = P*L*U as computed by DGETRF. */
|
|
/* On exit, if INFO = 0, the inverse of the original matrix A. */
|
|
|
|
/* LDA (input) INTEGER */
|
|
/* The leading dimension of the array A. LDA >= max(1,N). */
|
|
|
|
/* IPIV (input) INTEGER array, dimension (N) */
|
|
/* The pivot indices from DGETRF; for 1<=i<=N, row i of the */
|
|
/* matrix was interchanged with row IPIV(i). */
|
|
|
|
/* WORK (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) */
|
|
/* On exit, if INFO=0, then WORK(1) returns the optimal LWORK. */
|
|
|
|
/* LWORK (input) INTEGER */
|
|
/* The dimension of the array WORK. LWORK >= max(1,N). */
|
|
/* For optimal performance LWORK >= N*NB, where NB is */
|
|
/* the optimal blocksize returned by ILAENV. */
|
|
|
|
/* If LWORK = -1, then a workspace query is assumed; the routine */
|
|
/* only calculates the optimal size of the WORK array, returns */
|
|
/* this value as the first entry of the WORK array, and no error */
|
|
/* message related to LWORK is issued by XERBLA. */
|
|
|
|
/* 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 matrix is */
|
|
/* singular and its inverse could not be computed. */
|
|
|
|
/* ===================================================================== */
|
|
|
|
/* .. Parameters .. */
|
|
/* .. */
|
|
/* .. Local Scalars .. */
|
|
/* .. */
|
|
/* .. External Functions .. */
|
|
/* .. */
|
|
/* .. External Subroutines .. */
|
|
/* .. */
|
|
/* .. Intrinsic Functions .. */
|
|
/* .. */
|
|
/* .. Executable Statements .. */
|
|
|
|
/* Test the input parameters. */
|
|
|
|
/* Parameter adjustments */
|
|
a_dim1 = *lda;
|
|
a_offset = 1 + a_dim1;
|
|
a -= a_offset;
|
|
--ipiv;
|
|
--work;
|
|
|
|
/* Function Body */
|
|
*info = 0;
|
|
nb = ilaenv_(&c__1, "DGETRI", " ", n, &c_n1, &c_n1, &c_n1);
|
|
lwkopt = *n * nb;
|
|
work[1] = (doublereal) lwkopt;
|
|
lquery = *lwork == -1;
|
|
if (*n < 0) {
|
|
*info = -1;
|
|
} else if (*lda < max(1,*n)) {
|
|
*info = -3;
|
|
} else if (*lwork < max(1,*n) && ! lquery) {
|
|
*info = -6;
|
|
}
|
|
if (*info != 0) {
|
|
i__1 = -(*info);
|
|
xerbla_("DGETRI", &i__1);
|
|
return 0;
|
|
} else if (lquery) {
|
|
return 0;
|
|
}
|
|
|
|
/* Quick return if possible */
|
|
|
|
if (*n == 0) {
|
|
return 0;
|
|
}
|
|
|
|
/* Form inv(U). If INFO > 0 from DTRTRI, then U is singular, */
|
|
/* and the inverse is not computed. */
|
|
|
|
dtrtri_("Upper", "Non-unit", n, &a[a_offset], lda, info);
|
|
if (*info > 0) {
|
|
return 0;
|
|
}
|
|
|
|
nbmin = 2;
|
|
ldwork = *n;
|
|
if (nb > 1 && nb < *n) {
|
|
/* Computing MAX */
|
|
i__1 = ldwork * nb;
|
|
iws = max(i__1,1);
|
|
if (*lwork < iws) {
|
|
nb = *lwork / ldwork;
|
|
/* Computing MAX */
|
|
i__1 = 2, i__2 = ilaenv_(&c__2, "DGETRI", " ", n, &c_n1, &c_n1, &
|
|
c_n1);
|
|
nbmin = max(i__1,i__2);
|
|
}
|
|
} else {
|
|
iws = *n;
|
|
}
|
|
|
|
/* Solve the equation inv(A)*L = inv(U) for inv(A). */
|
|
|
|
if (nb < nbmin || nb >= *n) {
|
|
|
|
/* Use unblocked code. */
|
|
|
|
for (j = *n; j >= 1; --j) {
|
|
|
|
/* Copy current column of L to WORK and replace with zeros. */
|
|
|
|
i__1 = *n;
|
|
for (i__ = j + 1; i__ <= i__1; ++i__) {
|
|
work[i__] = a[i__ + j * a_dim1];
|
|
a[i__ + j * a_dim1] = 0.;
|
|
/* L10: */
|
|
}
|
|
|
|
/* Compute current column of inv(A). */
|
|
|
|
if (j < *n) {
|
|
i__1 = *n - j;
|
|
dgemv_("No transpose", n, &i__1, &c_b20, &a[(j + 1) * a_dim1
|
|
+ 1], lda, &work[j + 1], &c__1, &c_b22, &a[j * a_dim1
|
|
+ 1], &c__1);
|
|
}
|
|
/* L20: */
|
|
}
|
|
} else {
|
|
|
|
/* Use blocked code. */
|
|
|
|
nn = (*n - 1) / nb * nb + 1;
|
|
i__1 = -nb;
|
|
for (j = nn; i__1 < 0 ? j >= 1 : j <= 1; j += i__1) {
|
|
/* Computing MIN */
|
|
i__2 = nb, i__3 = *n - j + 1;
|
|
jb = min(i__2,i__3);
|
|
|
|
/* Copy current block column of L to WORK and replace with */
|
|
/* zeros. */
|
|
|
|
i__2 = j + jb - 1;
|
|
for (jj = j; jj <= i__2; ++jj) {
|
|
i__3 = *n;
|
|
for (i__ = jj + 1; i__ <= i__3; ++i__) {
|
|
work[i__ + (jj - j) * ldwork] = a[i__ + jj * a_dim1];
|
|
a[i__ + jj * a_dim1] = 0.;
|
|
/* L30: */
|
|
}
|
|
/* L40: */
|
|
}
|
|
|
|
/* Compute current block column of inv(A). */
|
|
|
|
if (j + jb <= *n) {
|
|
i__2 = *n - j - jb + 1;
|
|
dgemm_("No transpose", "No transpose", n, &jb, &i__2, &c_b20,
|
|
&a[(j + jb) * a_dim1 + 1], lda, &work[j + jb], &
|
|
ldwork, &c_b22, &a[j * a_dim1 + 1], lda);
|
|
}
|
|
dtrsm_("Right", "Lower", "No transpose", "Unit", n, &jb, &c_b22, &
|
|
work[j], &ldwork, &a[j * a_dim1 + 1], lda);
|
|
/* L50: */
|
|
}
|
|
}
|
|
|
|
/* Apply column interchanges. */
|
|
|
|
for (j = *n - 1; j >= 1; --j) {
|
|
jp = ipiv[j];
|
|
if (jp != j) {
|
|
dswap_(n, &a[j * a_dim1 + 1], &c__1, &a[jp * a_dim1 + 1], &c__1);
|
|
}
|
|
/* L60: */
|
|
}
|
|
|
|
work[1] = (doublereal) iws;
|
|
return 0;
|
|
|
|
/* End of DGETRI */
|
|
|
|
} /* dgetri_ */
|