chpcon(3P) Sun Performance Library chpcon(3P)NAMEchpcon - estimate 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
SUBROUTINE CHPCON(UPLO, N, A, IPIVOT, ANORM, RCOND, WORK, INFO)
CHARACTER * 1 UPLO
COMPLEX A(*), WORK(*)
INTEGER N, INFO
INTEGER IPIVOT(*)
REAL ANORM, RCOND
SUBROUTINE CHPCON_64(UPLO, N, A, IPIVOT, ANORM, RCOND, WORK, INFO)
CHARACTER * 1 UPLO
COMPLEX A(*), WORK(*)
INTEGER*8 N, INFO
INTEGER*8 IPIVOT(*)
REAL ANORM, RCOND
F95 INTERFACE
SUBROUTINE HPCON(UPLO, [N], A, IPIVOT, ANORM, RCOND, [WORK], [INFO])
CHARACTER(LEN=1) :: UPLO
COMPLEX, DIMENSION(:) :: A, WORK
INTEGER :: N, INFO
INTEGER, DIMENSION(:) :: IPIVOT
REAL :: ANORM, RCOND
SUBROUTINE HPCON_64(UPLO, [N], A, IPIVOT, ANORM, RCOND, [WORK], [INFO])
CHARACTER(LEN=1) :: UPLO
COMPLEX, DIMENSION(:) :: A, WORK
INTEGER(8) :: N, INFO
INTEGER(8), DIMENSION(:) :: IPIVOT
REAL :: ANORM, RCOND
C INTERFACE
#include <sunperf.h>
void chpcon(char uplo, int n, complex *a, int *ipivot, float anorm,
float *rcond, int *info);
void chpcon_64(char uplo, long n, complex *a, long *ipivot, float
anorm, float *rcond, long *info);
PURPOSEchpcon 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
UPLO (input)
Specifies whether the details of the factorization are stored
as an upper or lower triangular matrix. = 'U': Upper trian‐
gular, form is A = U*D*U**H;
= 'L': Lower triangular, form is A = L*D*L**H.
N (input) The order of the matrix A. N >= 0.
A (input) 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.
IPIVOT (input) (input) INTEGER array, dimension (N)
Details of the interchanges and the block structure of D as
determined by CHPTRF.
ANORM (input)
The 1-norm of the original matrix A.
RCOND (output)
The reciprocal of the condition number of the matrix A, com‐
puted as RCOND = 1/(ANORM * AINVNM), where AINVNM is an esti‐
mate of the 1-norm of inv(A) computed in this routine.
WORK (workspace)
COMPLEX array, dimension(2*N)
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
6 Mar 2009 chpcon(3P)
