dspcon(3) [centos man page]

```dspcon.f(3)							      LAPACK							       dspcon.f(3)

NAME
dspcon.f -

SYNOPSIS
Functions/Subroutines
subroutine dspcon (UPLO, N, AP, IPIV, ANORM, RCOND, WORK, IWORK, INFO)
DSPCON

Function/Subroutine Documentation
subroutine dspcon (characterUPLO, integerN, double precision, dimension( * )AP, integer, dimension( * )IPIV, double precisionANORM, double
precisionRCOND, double precision, dimension( * )WORK, integer, dimension( * )IWORK, integerINFO)
DSPCON

Purpose:

DSPCON estimates the reciprocal of the condition number (in the
1-norm) of a real symmetric packed matrix A using the factorization
A = U*D*U**T or A = L*D*L**T computed by DSPTRF.

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
Specifies whether the details of the factorization are stored
as an upper or lower triangular matrix.
= 'U':  Upper triangular, form is A = U*D*U**T;
= 'L':  Lower triangular, form is A = L*D*L**T.

N

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

AP

AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)
The block diagonal matrix D and the multipliers used to
obtain the factor U or L as computed by DSPTRF, stored as a
packed triangular matrix.

IPIV

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

ANORM

ANORM is DOUBLE PRECISION
The 1-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/(ANORM * AINVNM), where AINVNM is an
estimate of the 1-norm of inv(A) computed in this routine.

WORK

WORK is DOUBLE PRECISION array, dimension (2*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 125 of file dspcon.f.

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

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

Check Out this Related Man Page

```DSPCON(l)								 )								 DSPCON(l)

NAME
DSPCON  -  estimate  the reciprocal of the condition number (in the 1-norm) of a real symmetric packed matrix A using the factorization A =
U*D*U**T or A = L*D*L**T computed by DSPTRF

SYNOPSIS
SUBROUTINE DSPCON( UPLO, N, AP, IPIV, ANORM, RCOND, WORK, IWORK, INFO )

CHARACTER	  UPLO

INTEGER	  INFO, N

DOUBLE	  PRECISION ANORM, RCOND

INTEGER	  IPIV( * ), IWORK( * )

DOUBLE	  PRECISION AP( * ), WORK( * )

PURPOSE
DSPCON estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric packed matrix A using  the  factorization  A  =
U*D*U**T  or A = L*D*L**T computed by DSPTRF.  An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is com-
puted as RCOND = 1 / (ANORM * norm(inv(A))).

ARGUMENTS
UPLO    (input) CHARACTER*1
Specifies whether the details of the factorization are stored as an upper or lower triangular matrix.  =  'U':	Upper  triangular,
form is A = U*D*U**T;
= 'L':  Lower triangular, form is A = L*D*L**T.

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

AP      (input) DOUBLE PRECISION array, dimension (N*(N+1)/2)
The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSPTRF, stored as a packed triangu-
lar matrix.

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

ANORM   (input) DOUBLE PRECISION
The 1-norm of the original matrix A.

RCOND   (output) DOUBLE PRECISION
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) DOUBLE PRECISION array, dimension (2*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 							 DSPCON(l)```
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