dgetrf (3)  Linux Manuals
NAME
dgetrf.f 
SYNOPSIS
Functions/Subroutines
subroutine dgetrf (M, N, A, LDA, IPIV, INFO)
DGETRF
Function/Subroutine Documentation
subroutine dgetrf (integerM, integerN, double precision, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, integerINFO)
DGETRF
Purpose:

DGETRF computes an LU factorization of a general MbyN 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 rightlooking Level 3 BLAS version of the algorithm.
Parameters:

M
M is INTEGER The number of rows of the matrix A. M >= 0.
NN is INTEGER The number of columns of the matrix A. N >= 0.
AA is DOUBLE PRECISION array, dimension (LDA,N) On entry, the MbyN 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.
LDALDA is INTEGER The leading dimension of the array A. LDA >= max(1,M).
IPIVIPIV 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).
INFOINFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith 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.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 November 2011
Definition at line 109 of file dgetrf.f.
Author
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