dgetrf - compute an LU factorization of a general M-by-N matrix A using partial pivoting with row interchanges
SUBROUTINE DGETRF( M, N, A, LDA, IPIVOT, INFO) INTEGER M, N, LDA, INFO INTEGER IPIVOT(*) DOUBLE PRECISION A(LDA,*)
SUBROUTINE DGETRF_64( M, N, A, LDA, IPIVOT, INFO) INTEGER*8 M, N, LDA, INFO INTEGER*8 IPIVOT(*) DOUBLE PRECISION A(LDA,*)
SUBROUTINE GETRF( [M], [N], A, [LDA], IPIVOT, [INFO]) INTEGER :: M, N, LDA, INFO INTEGER, DIMENSION(:) :: IPIVOT REAL(8), DIMENSION(:,:) :: A
SUBROUTINE GETRF_64( [M], [N], A, [LDA], IPIVOT, [INFO]) INTEGER(8) :: M, N, LDA, INFO INTEGER(8), DIMENSION(:) :: IPIVOT REAL(8), DIMENSION(:,:) :: A
#include <sunperf.h>
void dgetrf(int m, int n, double *a, int lda, int *ipivot, int *info);
void dgetrf_64(long m, long n, double *a, long lda, long *ipivot, long *info);
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.
= 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.