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# spocon.f(3) [centos man page]

```spocon.f(3)							      LAPACK							       spocon.f(3)

NAME
spocon.f -

SYNOPSIS
Functions/Subroutines
subroutine spocon (UPLO, N, A, LDA, ANORM, RCOND, WORK, IWORK, INFO)
SPOCON

Function/Subroutine Documentation
subroutine spocon (characterUPLO, integerN, real, dimension( lda, * )A, integerLDA, realANORM, realRCOND, real, dimension( * )WORK, integer,
dimension( * )IWORK, integerINFO)
SPOCON

Purpose:

SPOCON estimates the reciprocal of the condition number (in the
1-norm) of a real symmetric positive definite matrix using the
Cholesky factorization A = U**T*U or A = L*L**T computed by SPOTRF.

An estimate is obtained for norm(inv(A)), and the reciprocal of the
condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).

Parameters:
UPLO

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

N

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

A

A is REAL array, dimension (LDA,N)
The triangular factor U or L from the Cholesky factorization
A = U**T*U or A = L*L**T, as computed by SPOTRF.

LDA

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

ANORM

ANORM is REAL
The 1-norm (or infinity-norm) of the symmetric matrix A.

RCOND

RCOND is REAL
The reciprocal of the condition number of the matrix A,
computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an
estimate of the 1-norm of inv(A) computed in this routine.

WORK

WORK is REAL array, dimension (3*N)

IWORK

IWORK is INTEGER array, dimension (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 121 of file spocon.f.

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

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

## Check Out this Related Man Page

```SPOCON(l)								 )								 SPOCON(l)

NAME
SPOCON  -  estimate  the reciprocal of the condition number (in the 1-norm) of a real symmetric positive definite matrix using the Cholesky
factorization A = U**T*U or A = L*L**T computed by SPOTRF

SYNOPSIS
SUBROUTINE SPOCON( UPLO, N, A, LDA, ANORM, RCOND, WORK, IWORK, INFO )

CHARACTER	  UPLO

INTEGER	  INFO, LDA, N

REAL 	  ANORM, RCOND

INTEGER	  IWORK( * )

REAL 	  A( LDA, * ), WORK( * )

PURPOSE
SPOCON estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric positive definite  matrix  using  the  Cholesky
factorization  A  = U**T*U or A = L*L**T computed by SPOTRF.  An estimate is obtained for norm(inv(A)), and the reciprocal of the condition
number is computed as RCOND = 1 / (ANORM * norm(inv(A))).

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

N       (input) INTEGER
The order of the matrix A.  N >= 0.

A       (input) REAL array, dimension (LDA,N)
The triangular factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T, as computed by SPOTRF.

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

ANORM   (input) REAL
The 1-norm (or infinity-norm) of the symmetric matrix A.

RCOND   (output) REAL
The reciprocal of the condition number of the matrix A, computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an estimate of  the
1-norm of inv(A) computed in this routine.

WORK    (workspace) REAL array, dimension (3*N)

IWORK   (workspace) INTEGER array, dimension (N)

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

LAPACK version 3.0						   15 June 2000 							 SPOCON(l)```