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

NAME
       SRC/zla_porpvgrw.f

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

Function/Subroutine Documentation
   double precision function zla_porpvgrw (character*1 uplo, integer ncols,
       complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension(
       ldaf, * ) af, integer ldaf, double precision, dimension( * ) work)
       ZLA_PORPVGRW computes the reciprocal pivot growth factor
       norm(A)/norm(U) for a symmetric or Hermitian positive-definite matrix.

       Purpose:


           !>
           !>
           !> ZLA_PORPVGRW computes the reciprocal pivot growth factor
           !> norm(A)/norm(U). The  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*16 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*16 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 ZPOTRF.
           !>

           LDAF

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

           WORK

           !>          WORK is DOUBLE PRECISION array, dimension (2*N)
           !>

       Author
           Univ. of Tennessee


           Univ. of California Berkeley


           Univ. of Colorado Denver


           NAG Ltd.

       Definition at line 105 of file zla_porpvgrw.f.

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

LAPACK                          Version 3.12.0           SRC/zla_porpvgrw.f(3)