Contents
zhpev - compute all the eigenvalues and, optionally, eigen-
vectors of a complex Hermitian matrix in packed storage
SUBROUTINE ZHPEV(JOBZ, UPLO, N, A, W, Z, LDZ, WORK, WORK2, INFO)
CHARACTER * 1 JOBZ, UPLO
DOUBLE COMPLEX A(*), Z(LDZ,*), WORK(*)
INTEGER N, LDZ, INFO
DOUBLE PRECISION W(*), WORK2(*)
SUBROUTINE ZHPEV_64(JOBZ, UPLO, N, A, W, Z, LDZ, WORK, WORK2, INFO)
CHARACTER * 1 JOBZ, UPLO
DOUBLE COMPLEX A(*), Z(LDZ,*), WORK(*)
INTEGER*8 N, LDZ, INFO
DOUBLE PRECISION W(*), WORK2(*)
F95 INTERFACE
SUBROUTINE HPEV(JOBZ, UPLO, [N], A, W, Z, [LDZ], [WORK], [WORK2],
[INFO])
CHARACTER(LEN=1) :: JOBZ, UPLO
COMPLEX(8), DIMENSION(:) :: A, WORK
COMPLEX(8), DIMENSION(:,:) :: Z
INTEGER :: N, LDZ, INFO
REAL(8), DIMENSION(:) :: W, WORK2
SUBROUTINE HPEV_64(JOBZ, UPLO, [N], A, W, Z, [LDZ], [WORK], [WORK2],
[INFO])
CHARACTER(LEN=1) :: JOBZ, UPLO
COMPLEX(8), DIMENSION(:) :: A, WORK
COMPLEX(8), DIMENSION(:,:) :: Z
INTEGER(8) :: N, LDZ, INFO
REAL(8), DIMENSION(:) :: W, WORK2
C INTERFACE
#include <sunperf.h>
void zhpev(char jobz, char uplo, int n, doublecomplex *a,
double *w, doublecomplex *z, int ldz, int *info);
void zhpev_64(char jobz, char uplo, long n, doublecomplex
*a, double *w, doublecomplex *z, long ldz, long
*info);
zhpev computes all the eigenvalues and, optionally, eigen-
vectors of a complex Hermitian matrix in packed storage.
JOBZ (input)
= 'N': Compute eigenvalues only;
= 'V': Compute eigenvalues and eigenvectors.
UPLO (input)
= 'U': Upper triangle of A is stored;
= 'L': Lower triangle of A is stored.
N (input) The order of the matrix A. N >= 0.
A (input/output) COMPLEX*16 array, dimension (N*(N+1)/2)
On entry, the upper or lower triangle of the Her-
mitian matrix A, packed columnwise in a linear
array. The j-th column of A is stored in the
array A as follows: if UPLO = 'U', A(i + (j-
1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', A(i +
(j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n.
On exit, A is overwritten by values generated dur-
ing the reduction to tridiagonal form. If UPLO =
'U', the diagonal and first superdiagonal of the
tridiagonal matrix T overwrite the corresponding
elements of A, and if UPLO = 'L', the diagonal and
first subdiagonal of T overwrite the corresponding
elements of A.
W (output) DOUBLE PRECISION array, dimension (N)
If INFO = 0, the eigenvalues in ascending order.
Z (input) COMPLEX*16 array, dimension (LDZ, N)
If JOBZ = 'V', then if INFO = 0, Z contains the
orthonormal eigenvectors of the matrix A, with the
i-th column of Z holding the eigenvector associ-
ated with W(i). If JOBZ = 'N', then Z is not
referenced.
LDZ (input)
The leading dimension of the array Z. LDZ >= 1,
and if JOBZ = 'V', LDZ >= max(1,N).
WORK (workspace)
COMPLEX*16 array, dimension(MAX(1,2*N-1))
WORK2 (workspace)
DOUBLE PRECISION array, dimension(max(1,3*N-2))
INFO (output)
= 0: successful exit.
< 0: if INFO = -i, the i-th argument had an ille-
gal value.
> 0: if INFO = i, the algorithm failed to con-
verge; i off-diagonal elements of an intermediate
tridiagonal form did not converge to zero.