zgecon.f man page

zgecon.f —

Synopsis

Functions/Subroutines

subroutine zgecon (NORM, N, A, LDA, ANORM, RCOND, WORK, RWORK, INFO)
ZGECON

Function/Subroutine Documentation

subroutine zgecon (characterNORM, integerN, complex*16, dimension( lda, * )A, integerLDA, double precisionANORM, double precisionRCOND, complex*16, dimension( * )WORK, double precision, dimension( * )RWORK, integerINFO)

ZGECON

Purpose:

ZGECON 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 ZGETRF.

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)) ).

Parameters:

NORM

NORM is CHARACTER*1
Specifies whether the 1-norm condition number or the
infinity-norm condition number is required:
= '1' or 'O':  1-norm;
= 'I':         Infinity-norm.

N

N is INTEGER
The order of the matrix A.  N >= 0.

A

A is COMPLEX*16 array, dimension (LDA,N)
The factors L and U from the factorization A = P*L*U
as computed by ZGETRF.

LDA

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

ANORM

ANORM is DOUBLE PRECISION
If NORM = '1' or 'O', the 1-norm of the original matrix A.
If NORM = 'I', the infinity-norm of the original matrix A.

RCOND

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

WORK

WORK is COMPLEX*16 array, dimension (2*N)

RWORK

RWORK is DOUBLE PRECISION array, dimension (2*N)

INFO

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

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Definition at line 124 of file zgecon.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

zgecon(3) is an alias of zgecon.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK