zppcon (l)  Linux Man Pages
zppcon: estimates the reciprocal of the condition number (in the 1norm) of a complex Hermitian positive definite packed matrix using the Cholesky factorization A = U**H*U or A = L*L**H computed by ZPPTRF
Command to display zppcon
manual in Linux: $ man l zppcon
NAME
ZPPCON  estimates the reciprocal of the condition number (in the 1norm) of a complex Hermitian positive definite packed matrix using the Cholesky factorization A = U**H*U or A = L*L**H computed by ZPPTRF
SYNOPSIS
 SUBROUTINE ZPPCON(

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

CHARACTER
UPLO

INTEGER
INFO, N

DOUBLE
PRECISION ANORM, RCOND

DOUBLE
PRECISION RWORK( * )

COMPLEX*16
AP( * ), WORK( * )
PURPOSE
ZPPCON estimates the reciprocal of the condition number (in the
1norm) of a complex Hermitian positive definite packed matrix using
the Cholesky factorization A = U**H*U or A = L*L**H computed by
ZPPTRF.
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

= aqUaq: Upper triangle of A is stored;
= aqLaq: Lower triangle of A is stored.
 N (input) INTEGER

The order of the matrix A. N >= 0.
 AP (input) COMPLEX*16 array, dimension (N*(N+1)/2)

The triangular factor U or L from the Cholesky factorization
A = U**H*U or A = L*L**H, packed columnwise in a linear
array. The jth column of U or L is stored in the array AP
as follows:
if UPLO = aqUaq, AP(i + (j1)*j/2) = U(i,j) for 1<=i<=j;
if UPLO = aqLaq, AP(i + (j1)*(2nj)/2) = L(i,j) for j<=i<=n.
 ANORM (input) DOUBLE PRECISION

The 1norm (or infinitynorm) of the Hermitian 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 1norm of inv(A) computed in this routine.
 WORK (workspace) COMPLEX*16 array, dimension (2*N)

 RWORK (workspace) DOUBLE PRECISION array, dimension (N)

 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
Pages related to zppcon
 zppcon (3)
 zppequ (l)  computes row and column scalings intended to equilibrate a Hermitian positive definite matrix A in packed storage and reduce its condition number (with respect to the twonorm)
 zpprfs (l)  improves the computed solution to a system of linear equations when the coefficient matrix is Hermitian positive definite and packed, and provides error bounds and backward error estimates for the solution
 zppsv (l)  computes the solution to a complex system of linear equations A * X = B,
 zppsvx (l)  uses the Cholesky factorization A = U**H*U or A = L*L**H to compute the solution to a complex system of linear equations A * X = B,
 zpptrf (l)  computes the Cholesky factorization of a complex Hermitian positive definite matrix A stored in packed format
 zpptri (l)  computes the inverse of a complex Hermitian positive definite matrix A using the Cholesky factorization A = U**H*U or A = L*L**H computed by ZPPTRF
 zpptrs (l)  solves a system of linear equations A*X = B with a Hermitian positive definite matrix A in packed storage using the Cholesky factorization A = U**H*U or A = L*L**H computed by ZPPTRF