ZGETRF(l)		LAPACK routine (version	1.1)		    ZGETRF(l)

NAME
  ZGETRF - 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, IPIV, INFO )

      INTEGER	     INFO, LDA,	M, N

      INTEGER	     IPIV( * )

      COMPLEX*16     A(	LDA, * )

PURPOSE
  ZGETRF computes an LU	factorization of a general M-by-N matrix A using par-
  tial 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.

ARGUMENTS

  M	  (input) INTEGER
	  The number of	rows of	the matrix A.  M >= 0.

  N	  (input) INTEGER
	  The number of	columns	of the matrix A.  N >= 0.

  A	  (input/output) COMPLEX*16 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.

  LDA	  (input) INTEGER
	  The leading dimension	of the array A.	 LDA >=	max(1,M).

  IPIV	  (output) 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).

  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 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.


Back to the listing of computational routines for linear equations