# dla_gerpvgrw.f (3) - Linux Manuals

dla_gerpvgrw.f -

## SYNOPSIS

### Functions/Subroutines

DOUBLE PRECISION function dla_gerpvgrw (N, NCOLS, A, LDA, AF, LDAF)
DLA_GERPVGRW

## Function/Subroutine Documentation

### DOUBLE PRECISION function dla_gerpvgrw (integerN, integerNCOLS, double precision, dimension( lda, * )A, integerLDA, double precision, dimension( ldaf, * )AF, integerLDAF)

DLA_GERPVGRW

Purpose:

``` DLA_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 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 factors L and U from the factorization
A = P*L*U as computed by DGETRF.
```

LDAF

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

Author:

Univ. of Tennessee

Univ. of California Berkeley