zgetrf(3P) Sun Performance Library zgetrf(3P)NAMEzgetrf - compute an LU factorization of a general M-by-N matrix A using
partial pivoting with row interchanges
SYNOPSIS
SUBROUTINE ZGETRF(M, N, A, LDA, IPIVOT, INFO)
DOUBLE COMPLEX A(LDA,*)
INTEGER M, N, LDA, INFO
INTEGER IPIVOT(*)
SUBROUTINE ZGETRF_64(M, N, A, LDA, IPIVOT, INFO)
DOUBLE COMPLEX A(LDA,*)
INTEGER*8 M, N, LDA, INFO
INTEGER*8 IPIVOT(*)
F95 INTERFACE
SUBROUTINE GETRF([M], [N], A, [LDA], IPIVOT, [INFO])
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER :: M, N, LDA, INFO
INTEGER, DIMENSION(:) :: IPIVOT
SUBROUTINE GETRF_64([M], [N], A, [LDA], IPIVOT, [INFO])
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER(8) :: M, N, LDA, INFO
INTEGER(8), DIMENSION(:) :: IPIVOT
C INTERFACE
#include <sunperf.h>
void zgetrf(int m, int n, doublecomplex *a, int lda, int *ipivot, int
*info);
void zgetrf_64(long m, long n, doublecomplex *a, long lda, long
*ipivot, long *info);
PURPOSEzgetrf 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 diago‐
nal 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) The number of rows of the matrix A. M >= 0.
N (input) The number of columns of the matrix A. N >= 0.
A (input/output)
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)
The leading dimension of the array A. LDA >= max(1,M).
IPIVOT (output)
The pivot indices; for 1 <= i <= min(M,N), row i of the
matrix was interchanged with row IPIVOT(i).
INFO (output)
= 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.
6 Mar 2009 zgetrf(3P)
