NAME

SYNOPSIS

  SUBROUTINE SGETF2( M, N, A, LDA, IPIV, INFO)
  INTEGER M, N, LDA, INFO
  INTEGER IPIV(*)
  REAL A(LDA,*)
 
  SUBROUTINE SGETF2_64( M, N, A, LDA, IPIV, INFO)
  INTEGER*8 M, N, LDA, INFO
  INTEGER*8 IPIV(*)
  REAL A(LDA,*)
 

F95 INTERFACE

  SUBROUTINE GETF2( [M], [N], A, [LDA], IPIV, [INFO])
  INTEGER :: M, N, LDA, INFO
  INTEGER, DIMENSION(:) :: IPIV
  REAL, DIMENSION(:,:) :: A
 
  SUBROUTINE GETF2_64( [M], [N], A, [LDA], IPIV, [INFO])
  INTEGER(8) :: M, N, LDA, INFO
  INTEGER(8), DIMENSION(:) :: IPIV
  REAL, DIMENSION(:,:) :: A
 

C INTERFACE

void sgetf2(int m, int n, float *a, int lda, int *ipiv, int *info);

void sgetf2_64(long m, long n, float *a, long lda, long *ipiv, long *info);

PURPOSE

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)

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).

* IPIV (output)

The pivot indices; for 1 <= i <= min(M,N), row i of the matrix was interchanged with row IPIV(i).

* INFO (output)