SRC/cla_porpvgrw.f(3)      Library Functions Manual      SRC/cla_porpvgrw.f(3)

NAME
       SRC/cla_porpvgrw.f

SYNOPSIS
   Functions/Subroutines
       real function cla_porpvgrw (uplo, ncols, a, lda, af, ldaf, work)
           CLA_PORPVGRW computes the reciprocal pivot growth factor
           norm(A)/norm(U) for a symmetric or Hermitian positive-definite
           matrix.

Function/Subroutine Documentation
   real function cla_porpvgrw (character*1 uplo, integer ncols, complex,
       dimension( lda, * ) a, integer lda, complex, dimension( ldaf, * ) af,
       integer ldaf, real, dimension( * ) work)
       CLA_PORPVGRW computes the reciprocal pivot growth factor
       norm(A)/norm(U) for a symmetric or Hermitian positive-definite matrix.

       Purpose:


            CLA_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.

       Parameters
           UPLO

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

           NCOLS

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

           A

                     A is COMPLEX array, dimension (LDA,N)
                On entry, the N-by-N matrix A.

           LDA

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

           AF

                     AF is COMPLEX 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 CPOTRF.

           LDAF

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

           WORK

                     WORK is REAL array, dimension (2*N)

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 104 of file cla_porpvgrw.f.

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

LAPACK                          Version 3.12.0           SRC/cla_porpvgrw.f(3)