sstev - compute all eigenvalues and, optionally, eigenvectors of a real symmetric tridiagonal matrix A
SUBROUTINE SSTEV( JOBZ, N, DIAG, OFFD, Z, LDZ, WORK, INFO) CHARACTER * 1 JOBZ INTEGER N, LDZ, INFO REAL DIAG(*), OFFD(*), Z(LDZ,*), WORK(*)
SUBROUTINE SSTEV_64( JOBZ, N, DIAG, OFFD, Z, LDZ, WORK, INFO) CHARACTER * 1 JOBZ INTEGER*8 N, LDZ, INFO REAL DIAG(*), OFFD(*), Z(LDZ,*), WORK(*)
SUBROUTINE STEV( JOBZ, [N], DIAG, OFFD, Z, [LDZ], [WORK], [INFO]) CHARACTER(LEN=1) :: JOBZ INTEGER :: N, LDZ, INFO REAL, DIMENSION(:) :: DIAG, OFFD, WORK REAL, DIMENSION(:,:) :: Z
SUBROUTINE STEV_64( JOBZ, [N], DIAG, OFFD, Z, [LDZ], [WORK], [INFO]) CHARACTER(LEN=1) :: JOBZ INTEGER(8) :: N, LDZ, INFO REAL, DIMENSION(:) :: DIAG, OFFD, WORK REAL, DIMENSION(:,:) :: Z
#include <sunperf.h>
void sstev(char jobz, int n, float *diag, float *offd, float *z, int ldz, int *info);
void sstev_64(char jobz, long n, float *diag, float *offd, float *z, long ldz, long *info);
sstev computes all eigenvalues and, optionally, eigenvectors of a real symmetric tridiagonal matrix A.
= 'N': Compute eigenvalues only;
= 'V': Compute eigenvalues and eigenvectors.
OFFD(N)
need not
be set, but is used by the routine.
On exit, the contents of OFFD are destroyed.
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: if INFO = i, the algorithm failed to converge; i off-diagonal elements of OFFD did not converge to zero.