          SEARCH  NEW RPMS  DIRECTORIES  ABOUT  FAQ  VARIOUS  BLOG  DONATE  YUM REPOSITORY    MAN page from OpenSuSE 12.X lapack-man-3.3.1-15.1.noarch.rpm

# CGECON

Section: LAPACK routine (version 3.3.1) (1)
Updated: April 2011
Index

## NAME

LAPACK-3 - estimates the reciprocal of the condition number of a general complex matrix A, in either the 1-norm or the infinity-norm, using the LU factorization computed by CGETRF

## SYNOPSIS

SUBROUTINE CGECON(
NORM, N, A, LDA, ANORM, RCOND, WORK, RWORK,INFO )

CHARACTERNORM

INTEGERINFO, LDA, N

REALANORM, RCOND

REALRWORK( * )

COMPLEXA( LDA, * ), WORK( * )

## PURPOSE

CGECON estimates the reciprocal of the condition number of a generalcomplex matrix A, in either the 1-norm or the infinity-norm, usingthe LU factorization computed by CGETRF.
An estimate is obtained for norm(inv(A)), and the reciprocal of the
condition number is computed as

RCOND = 1 / ( norm(A) * norm(inv(A)) ).

## ARGUMENTS

NORM    (input) CHARACTER*1

Specifies whether the 1-norm condition number or the
infinity-norm condition number is required:

= aq1aq or aqOaq:  1-norm;

= aqIaq:         Infinity-norm.

N       (input) INTEGER

The order of the matrix A.  N >= 0.

A       (input) COMPLEX array, dimension (LDA,N)

The factors L and U from the factorization A = P*L*U
as computed by CGETRF.

LDA     (input) INTEGER

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

ANORM   (input) REAL

If NORM = aq1aq or aqOaq, the 1-norm of the original matrix A.
If NORM = aqIaq, the infinity-norm of the original matrix A.

RCOND   (output) REAL

The reciprocal of the condition number of the matrix A,
computed as RCOND = 1/(norm(A) * norm(inv(A))).

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

RWORK   (workspace) REAL array, dimension (2*N)

INFO    (output) INTEGER

= 0:  successful exit

< 0:  if INFO = -i, the i-th argument had an illegal value

## Index

NAME
SYNOPSIS
PURPOSE
ARGUMENTS

This document was created byman2html,using the manual pages.  