sgetf2(l) [redhat man page]

SGETF2(l)								 )								 SGETF2(l)

NAME

       SGETF2 - compute an LU factorization of a general m-by-n matrix A using partial pivoting with row interchanges

SYNOPSIS

       SUBROUTINE SGETF2( M, N, A, LDA, IPIV, INFO )

	   INTEGER	  INFO, LDA, M, N

	   INTEGER	  IPIV( * )

	   REAL 	  A( LDA, * )

PURPOSE

       SGETF2  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 2 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) REAL 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 ele-
	       ments 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 = -k, the k-th argument had an illegal value
	       > 0: if INFO = k, U(k,k) 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.

LAPACK version 3.0						   15 June 2000 							 SGETF2(l)

sgetf2.f(3)							      LAPACK							       sgetf2.f(3)

NAME

       sgetf2.f -

SYNOPSIS

   Functions/Subroutines
       subroutine sgetf2 (M, N, A, LDA, IPIV, INFO)
	   SGETF2

Function/Subroutine Documentation
   subroutine sgetf2 (integerM, integerN, real, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, integerINFO)
       SGETF2

       Purpose:

	    SGETF2 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 2 BLAS version of the algorithm.

       Parameters:
	   M

		     M is INTEGER
		     The number of rows of the matrix A.  M >= 0.

	   N

		     N is INTEGER
		     The number of columns of the matrix A.  N >= 0.

	   A

		     A is REAL 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

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

	   IPIV

		     IPIV 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).

	   INFO

		     INFO is INTEGER
		     = 0: successful exit
		     < 0: if INFO = -k, the k-th argument had an illegal value
		     > 0: if INFO = k, U(k,k) 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 sgetf2.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.1							  Sun May 26 2013						       sgetf2.f(3)