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CHPCON(1) LAPACK routine (version 3.2) CHPCON(1)

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

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

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**H;
= 'L': Lower triangular, form is A = L*D*L**H.
The order of the matrix A. N >= 0.
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.
Details of the interchanges and the block structure of D as determined by CHPTRF.
The 1-norm of the original matrix A.
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.
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
November 2008 LAPACK routine (version 3.2)