dsterf (3p)

Name

dsterf - compute all eigenvalues of a symmetric tridiagonal matrix using the Pal-Walker-Kahan variant of the QL or QR algorithm

Synopsis

SUBROUTINE DSTERF(N, D, E, INFO)

INTEGER N, INFO
DOUBLE PRECISION D(*), E(*)

SUBROUTINE DSTERF_64(N, D, E, INFO)

INTEGER*8 N, INFO
DOUBLE PRECISION D(*), E(*)




F95 INTERFACE
SUBROUTINE STERF(N, D, E, INFO)

INTEGER :: N, INFO
REAL(8), DIMENSION(:) :: D, E

SUBROUTINE STERF_64(N, D, E, INFO)

INTEGER(8) :: N, INFO
REAL(8), DIMENSION(:) :: D, E




C INTERFACE
#include <sunperf.h>

void dsterf(int n, double *d, double *e, int *info);

void dsterf_64(long n, double *d, double *e, long *info);

Description

Oracle Solaris Studio Performance Library                           dsterf(3P)



NAME
       dsterf  -  compute  all  eigenvalues  of a symmetric tridiagonal matrix
       using the Pal-Walker-Kahan variant of the QL or QR algorithm


SYNOPSIS
       SUBROUTINE DSTERF(N, D, E, INFO)

       INTEGER N, INFO
       DOUBLE PRECISION D(*), E(*)

       SUBROUTINE DSTERF_64(N, D, E, INFO)

       INTEGER*8 N, INFO
       DOUBLE PRECISION D(*), E(*)




   F95 INTERFACE
       SUBROUTINE STERF(N, D, E, INFO)

       INTEGER :: N, INFO
       REAL(8), DIMENSION(:) :: D, E

       SUBROUTINE STERF_64(N, D, E, INFO)

       INTEGER(8) :: N, INFO
       REAL(8), DIMENSION(:) :: D, E




   C INTERFACE
       #include <sunperf.h>

       void dsterf(int n, double *d, double *e, int *info);

       void dsterf_64(long n, double *d, double *e, long *info);



PURPOSE
       dsterf computes all eigenvalues of a symmetric tridiagonal matrix using
       the Pal-Walker-Kahan variant of the QL or QR algorithm.


ARGUMENTS
       N (input) The order of the matrix.  N >= 0.


       D (input/output)
                 On  entry, the n diagonal elements of the tridiagonal matrix.
                 On exit, if INFO = 0, the eigenvalues in ascending order.


       E (input/output)
                 On entry, the (n-1) subdiagonal elements of  the  tridiagonal
                 matrix.  On exit, E has been destroyed.


       INFO (output)
                 = 0:  successful exit
                 < 0:  if INFO = -i, the i-th argument had an illegal value
                 >  0:  the algorithm failed to find all of the eigenvalues in
                 a total of 30*N iterations; if INFO = i, then i elements of E
                 have not converged to zero.




                                  7 Nov 2015                        dsterf(3P)