# sla_gerpvgrw.f - Man Page

## Synopsis

### Functions/Subroutines

real function **sla_gerpvgrw** (**N**, NCOLS, A, **LDA**, AF, LDAF)**SLA_GERPVGRW**

## Function/Subroutine Documentation

### real function sla_gerpvgrw (integer N, integer NCOLS, real, dimension( lda, * ) A, integer LDA, real, dimension( ldaf, * ) AF, integer LDAF)

**SLA_GERPVGRW**

**Purpose:**

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

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

*A*A is REAL 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 REAL array, dimension (LDAF,N) The factors L and U from the factorization A = P*L*U as computed by SGETRF.

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

**Author:**Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Date:**December 2016

Definition at line 99 of file sla_gerpvgrw.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page sla_gerpvgrw(3) is an alias of sla_gerpvgrw.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK