# cla_herpvgrw.f man page

cla_herpvgrw.f —

## Synopsis

### Functions/Subroutines

REAL function **cla_herpvgrw** (UPLO, N, INFO, A, LDA, AF, LDAF, IPIV, WORK)**CLA_HERPVGRW**

## Function/Subroutine Documentation

### REAL function cla_herpvgrw (character*1UPLO, integerN, integerINFO, complex, dimension( lda, * )A, integerLDA, complex, dimension( ldaf, * )AF, integerLDAF, integer, dimension( * )IPIV, real, dimension( * )WORK)

**CLA_HERPVGRW**

**Purpose:**

CLA_HERPVGRW 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.

*N*N is INTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0.

*INFO*INFO is INTEGER The value of INFO returned from SSYTRF, .i.e., the pivot in column INFO is exactly 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 block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by CHETRF.

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

*IPIV*IPIV is INTEGER array, dimension (N) Details of the interchanges and the block structure of D as determined by CHETRF.

*WORK*WORK is COMPLEX array, dimension (2*N)

**Author:**-
Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Date:**November 2011

Definition at line 123 of file cla_herpvgrw.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

cla_herpvgrw(3) is an alias of cla_herpvgrw.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK