dla_porpvgrw.f(3) LAPACK dla_porpvgrw.f(3)NAME
dla_porpvgrw.f -
SYNOPSIS
Functions/Subroutines
DOUBLE PRECISION function dla_porpvgrw (UPLO, NCOLS, A, LDA, AF, LDAF,
WORK)
DLA_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 dla_porpvgrw (character*1UPLO, integerNCOLS,
double precision, dimension( lda, * )A, integerLDA, double precision,
dimension( ldaf, * )AF, integerLDAF, double precision, dimension( *
)WORK)
DLA_PORPVGRW computes the reciprocal pivot growth factor
norm(A)/norm(U) for a symmetric or Hermitian positive-definite matrix.
Purpose:
DLA_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 DOUBLE PRECISION 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 DOUBLE PRECISION 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 DPOTRF.
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.
Date:
September 2012
Definition at line 106 of file dla_porpvgrw.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 dla_porpvgrw.f(3)
