cppcon (l)  Linux Manuals
cppcon: 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 CPPTRF
Command to display cppcon
manual in Linux: $ man l cppcon
NAME
CPPCON  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 CPPTRF
SYNOPSIS
 SUBROUTINE CPPCON(

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

CHARACTER
UPLO

INTEGER
INFO, N

REAL
ANORM, RCOND

REAL
RWORK( * )

COMPLEX
AP( * ), WORK( * )
PURPOSE
CPPCON 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
CPPTRF.
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 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) REAL

The 1norm (or infinitynorm) of the Hermitian 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)

 RWORK (workspace) REAL array, dimension (N)

 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
Pages related to cppcon
 cppcon (3)
 cppequ (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)
 cpprfs (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
 cppsv (l)  computes the solution to a complex system of linear equations A * X = B,
 cppsvx (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,
 cpptrf (l)  computes the Cholesky factorization of a complex Hermitian positive definite matrix A stored in packed format
 cpptri (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 CPPTRF
 cpptrs (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 CPPTRF