Provided by: liblapack-doc_3.3.1-1_all

#### NAME

```       LAPACK-3 - computes the reciprocal pivot growth factor norm(A)/norm(U)

```

#### SYNOPSIS

```       DOUBLE PRECISION FUNCTION DLA_PORPVGRW( UPLO, NCOLS, A, LDA, AF, LDAF, WORK )

IMPLICIT     NONE

CHARACTER*1  UPLO

INTEGER      NCOLS, LDA, LDAF

DOUBLE       PRECISION A( LDA, * ), AF( LDAF, * ), WORK( * )

```

#### 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.

```

#### ARGUMENTS

```        UPLO    (input) CHARACTER*1
= 'U':  Upper triangle of A is stored;
= 'L':  Lower triangle of A is stored.

NCOLS   (input) INTEGER
The number of columns of the matrix A. NCOLS >= 0.

A       (input) DOUBLE PRECISION array, dimension (LDA,N)
On entry, the N-by-N matrix A.

LDA     (input) INTEGER
The leading dimension of the array A.  LDA >= max(1,N).

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

WORK    (input) DOUBLE PRECISION array, dimension (2*N)

LAPACK routine (version 3.2.2)          April 2011                      DLA_PORPVGRW(3lapack)
```