sspcon (l)  Linux Manuals
sspcon: estimates the reciprocal of the condition number (in the 1norm) of a real symmetric packed matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by SSPTRF
Command to display sspcon
manual in Linux: $ man l sspcon
NAME
SSPCON  estimates the reciprocal of the condition number (in the 1norm) of a real symmetric packed matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by SSPTRF
SYNOPSIS
 SUBROUTINE SSPCON(

UPLO, N, AP, IPIV, ANORM, RCOND, WORK, IWORK,
INFO )

CHARACTER
UPLO

INTEGER
INFO, N

REAL
ANORM, RCOND

INTEGER
IPIV( * ), IWORK( * )

REAL
AP( * ), WORK( * )
PURPOSE
SSPCON estimates the reciprocal of the condition number (in the
1norm) of a real symmetric packed matrix A using the factorization
A = U*D*U**T or A = L*D*L**T computed by SSPTRF.
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

Specifies whether the details of the factorization are stored
as an upper or lower triangular matrix.
= aqUaq: Upper triangular, form is A = U*D*U**T;
= aqLaq: Lower triangular, form is A = L*D*L**T.
 N (input) INTEGER

The order of the matrix A. N >= 0.
 AP (input) REAL 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 SSPTRF, stored as a
packed triangular matrix.
 IPIV (input) INTEGER array, dimension (N)

Details of the interchanges and the block structure of D
as determined by SSPTRF.
 ANORM (input) REAL

The 1norm of the original 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 1norm of inv(A) computed in this routine.
 WORK (workspace) REAL array, dimension (2*N)

 IWORK (workspace) INTEGER array, dimension (N)

 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
Pages related to sspcon
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 sspevd (l)  computes all the eigenvalues and, optionally, eigenvectors of a real symmetric matrix A in packed storage
 sspevx (l)  computes selected eigenvalues and, optionally, eigenvectors of a real symmetric matrix A in packed storage
 sspgst (l)  reduces a real symmetricdefinite generalized eigenproblem to standard form, using packed storage
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 sspgvd (l)  computes all the eigenvalues, and optionally, the eigenvectors of a real generalized symmetricdefinite eigenproblem, of the form A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x
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