chpcon.f3
Usage
Functions/Subroutines
subroutine chpcon (uplo, n, ap, ipiv, anorm, rcond, work, info)
CHPCON
Function/Subroutine Documentation
subroutine chpcon (character uplo, integer n, complex, dimension( * ) ap, integer, dimension( * ) ipiv, real anorm, real rcond, complex, dimension( * ) work, integer info)
CHPCON
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))). !>
Parameters
UPLO
!> UPLO is CHARACTER*1 !> 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. !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
AP
!> AP is 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
!> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by CHPTRF. !>
ANORM
!> ANORM is REAL !> The 1-norm of the original matrix A. !>
RCOND
!> RCOND is REAL !> 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. !>
WORK
!> WORK is COMPLEX array, dimension (2*N) !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 117 of file chpcon.f.
Releases
4 releases since Debian 7 (Wheezy); the text changed 3 times.