Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3 - computes the reciprocal pivot growth factor norm(A)/norm(U)

SYNOPSIS

       REAL FUNCTION SLA_PORPVGRW( UPLO, NCOLS, A, LDA, AF, LDAF, WORK )

           IMPLICIT  NONE

           CHARACTER*1
                     UPLO

           INTEGER   NCOLS, LDA, LDAF

           REAL      A( LDA, * ), AF( LDAF, * ), WORK( * )

PURPOSE

       SLA_PORPVGRW  computes  the  reciprocal  pivot  growth  factor  norm(A)/norm(U).  The "max
       absolute element" norm is used. If this is
        much less than 1, the stability of the LU factorization of the
        (equilibrated) matrix A could be poor. This also means that the
        solution X, estimated condition numbers, and error bounds could be
        unreliable.

ARGUMENTS

        UPLO    (input) CHARACTER*1
                = 'U':  Upper triangle of A is stored;
                = 'L':  Lower triangle of A is stored.

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

        A       (input) REAL array, dimension (LDA,N)
                On entry, the N-by-N matrix A.

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

        AF      (input) REAL array, dimension (LDAF,N)
                The triangular factor U or L from the Cholesky factorization
                A = U**T*U or A = L*L**T, as computed by SPOTRF.

        LDAF    (input) INTEGER
                The leading dimension of the array AF.  LDAF >= max(1,N).

        WORK    (input) REAL array, dimension (2*N)

    LAPACK routine (version 3.2.2)          April 2011                      SLA_PORPVGRW(3lapack)