Contents
zhpcon - 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 ZHPTRF
SUBROUTINE ZHPCON(UPLO, N, A, IPIVOT, ANORM, RCOND, WORK, INFO)
CHARACTER * 1 UPLO
DOUBLE COMPLEX A(*), WORK(*)
INTEGER N, INFO
INTEGER IPIVOT(*)
DOUBLE PRECISION ANORM, RCOND
SUBROUTINE ZHPCON_64(UPLO, N, A, IPIVOT, ANORM, RCOND, WORK, INFO)
CHARACTER * 1 UPLO
DOUBLE COMPLEX A(*), WORK(*)
INTEGER*8 N, INFO
INTEGER*8 IPIVOT(*)
DOUBLE PRECISION ANORM, RCOND
F95 INTERFACE
SUBROUTINE HPCON(UPLO, [N], A, IPIVOT, ANORM, RCOND, [WORK], [INFO])
CHARACTER(LEN=1) :: UPLO
COMPLEX(8), DIMENSION(:) :: A, WORK
INTEGER :: N, INFO
INTEGER, DIMENSION(:) :: IPIVOT
REAL(8) :: ANORM, RCOND
SUBROUTINE HPCON_64(UPLO, [N], A, IPIVOT, ANORM, RCOND, [WORK], [INFO])
CHARACTER(LEN=1) :: UPLO
COMPLEX(8), DIMENSION(:) :: A, WORK
INTEGER(8) :: N, INFO
INTEGER(8), DIMENSION(:) :: IPIVOT
REAL(8) :: ANORM, RCOND
C INTERFACE
#include <sunperf.h>
void zhpcon(char uplo, int n, doublecomplex *a, int *ipivot,
double anorm, double *rcond, int *info);
void zhpcon_64(char uplo, long n, doublecomplex *a, long
*ipivot, double anorm, double *rcond, long *info);
zhpcon 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 ZHPTRF.
An estimate is obtained for norm(inv(A)), and the reciprocal
of the condition number is computed as RCOND = 1 / (ANORM *
norm(inv(A))).
UPLO (input)
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 (input) The order of the matrix A. N >= 0.
A (input) COMPLEX*16 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
ZHPTRF, stored as a packed triangular matrix.
IPIVOT (input) INTEGER array, dimension (N)
Details of the interchanges and the block struc-
ture of D as determined by ZHPTRF.
ANORM (input)
The 1-norm of the original matrix A.
RCOND (output)
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 (workspace)
COMPLEX*16 array, dimension(2*N)
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an ille-
gal value