## Linux and UNIX Man Pages

Test Your Knowledge in Computers #157
Difficulty: Easy
The US Department of Defense declared TCP/IP as the standard for all military computer networking in March 1982,
True or False?

# cgecon.f(3) [debian man page]

```cgecon.f(3)							      LAPACK							       cgecon.f(3)

NAME
cgecon.f -

SYNOPSIS
Functions/Subroutines
subroutine cgecon (NORM, N, A, LDA, ANORM, RCOND, WORK, RWORK, INFO)
CGECON

Function/Subroutine Documentation
subroutine cgecon (characterNORM, integerN, complex, dimension( lda, * )A, integerLDA, realANORM, realRCOND, complex, dimension( * )WORK, real,
dimension( * )RWORK, integerINFO)
CGECON

Purpose:

CGECON 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.

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

LDA

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

ANORM

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

WORK

WORK is COMPLEX array, dimension (2*N)

RWORK

RWORK is REAL 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

NAG Ltd.

Date:
November 2011

Definition at line 124 of file cgecon.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.1							  Sun May 26 2013						       cgecon.f(3)```

## Check Out this Related Man Page

```cgecon.f(3)							      LAPACK							       cgecon.f(3)

NAME
cgecon.f -

SYNOPSIS
Functions/Subroutines
subroutine cgecon (NORM, N, A, LDA, ANORM, RCOND, WORK, RWORK, INFO)
CGECON

Function/Subroutine Documentation
subroutine cgecon (characterNORM, integerN, complex, dimension( lda, * )A, integerLDA, realANORM, realRCOND, complex, dimension( * )WORK, real,
dimension( * )RWORK, integerINFO)
CGECON

Purpose:

CGECON 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.

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

LDA

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

ANORM

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

WORK

WORK is COMPLEX array, dimension (2*N)

RWORK

RWORK is REAL 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

NAG Ltd.

Date:
November 2011

Definition at line 124 of file cgecon.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       cgecon.f(3)```