Homepage > Man Pages > Category > Subroutines
Homepage > Man Pages > Name > L

# LAPACK-3

## man page of LAPACK-3

### LAPACK-3: ZLA_HERCOND_X compute the infinity norm condition number of op(A) * diag(X) where X is a COMPLEX*16 vector

```NAME
LAPACK-3  - ZLA_HERCOND_X compute the infinity norm condition number of
op(A) * diag(X) where X is a COMPLEX*16 vector

SYNOPSIS
DOUBLE PRECISION FUNCTION ZLA_HERCOND_X( UPLO, N,  A,  LDA,  AF,  LDAF,
IPIV, X, INFO, WORK, RWORK )

IMPLICIT     NONE

CHARACTER    UPLO

INTEGER      N, LDA, LDAF, INFO

INTEGER      IPIV( * )

COMPLEX*16   A( LDA, * ), AF( LDAF, * ), WORK( * ), X( * )

DOUBLE       PRECISION RWORK( * )

PURPOSE
ZLA_HERCOND_X computes the infinity norm condition number of
op(A) * diag(X) where X is a COMPLEX*16 vector.

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

N       (input) INTEGER
The number of linear equations, i.e., the order of the
matrix A.  N >= 0.

A       (input) COMPLEX*16 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) COMPLEX*16 array, dimension (LDAF,N)
The block diagonal matrix D and the multipliers used to
obtain the factor U or L as computed by ZHETRF.

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

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

X       (input) COMPLEX*16 array, dimension (N)
The vector X in the formula op(A) * diag(X).

INFO    (output) INTEGER
= 0:  Successful exit.
i > 0:  The ith argument is invalid.

WORK    (input) COMPLEX*16 array, dimension (2*N).
Workspace.

RWORK   (input) DOUBLE PRECISION array, dimension (N).
Workspace.

LAPACK routine (version 3.2.1)March 2011                       LAPACK-3(3)
```