SRC/dgetf2.f(3)

NAME
SRC/dgetf2.f

SYNOPSIS

  Functions/Subroutines
subroutine dgetf2 (m, n, a, lda, ipiv, info)
DGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row interchanges (unblocked algorithm).

Function/Subroutine Documentation

  subroutine dgetf2 (integer m, integer n, double precision, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer info)

DGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row interchanges (unblocked algorithm).

Purpose:

     DGETF2 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 DOUBLE PRECISION 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.

Definition at line 107 of file dgetf2.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.