cspcon3
Part of cspcon.f(3).
Usage
Functions/Subroutines
subroutine cspcon (uplo, n, ap, ipiv, anorm, rcond, work, info)
CSPCON
Function/Subroutine Documentation
subroutine cspcon (character uplo, integer n, complex, dimension( * ) ap, integer, dimension( * ) ipiv, real anorm, real rcond, complex, dimension( * ) work, integer info)
CSPCON
Purpose:
!> !> CSPCON estimates the reciprocal of the condition number (in the !> 1-norm) of a complex symmetric packed matrix A using the !> factorization A = U*D*U**T or A = L*D*L**T computed by CSPTRF. !> !> 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**T; !> = 'L': Lower triangular, form is A = L*D*L**T. !>
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 CSPTRF, 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 CSPTRF. !>
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 cspcon.f.
Releases
14 releases since Debian 1.3 (Bo); the text changed 10 times.