chpcon (l)  Linux Man Pages
chpcon: estimates the reciprocal of the condition number of a complex Hermitian packed matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by CHPTRF
Command to display chpcon
manual in Linux: $ man l chpcon
NAME
CHPCON  estimates the reciprocal of the condition number of a complex Hermitian packed matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by CHPTRF
SYNOPSIS
 SUBROUTINE CHPCON(

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

CHARACTER
UPLO

INTEGER
INFO, N

REAL
ANORM, RCOND

INTEGER
IPIV( * )

COMPLEX
AP( * ), WORK( * )
PURPOSE
CHPCON estimates the reciprocal of the condition number of a complex
Hermitian packed matrix A using the factorization A = U*D*U**H or
A = L*D*L**H computed by CHPTRF.
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**H;
= aqLaq: Lower triangular, form is A = L*D*L**H.
 N (input) INTEGER

The order of the matrix A. N >= 0.
 AP (input) COMPLEX 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 CHPTRF, 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 CHPTRF.
 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) COMPLEX array, dimension (2*N)

 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
Pages related to chpcon
 chpcon (3)
 chpev (l)  computes all the eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix in packed storage
 chpevd (l)  computes all the eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A in packed storage
 chpevx (l)  computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A in packed storage
 chpgst (l)  reduces a complex Hermitiandefinite generalized eigenproblem to standard form, using packed storage
 chpgv (l)  computes all the eigenvalues and, optionally, the eigenvectors of a complex generalized Hermitiandefinite eigenproblem, of the form A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x
 chpgvd (l)  computes all the eigenvalues and, optionally, the eigenvectors of a complex generalized Hermitiandefinite eigenproblem, of the form A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x
 chpgvx (l)  computes selected eigenvalues and, optionally, eigenvectors of a complex generalized Hermitiandefinite eigenproblem, of the form A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x