dspev (3p)

Name

dspev - compute all the eigenvalues and, optionally, eigenvectors of a real symmetric matrix A in packed storage

Synopsis

SUBROUTINE DSPEV(JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, INFO)

CHARACTER*1 JOBZ, UPLO
INTEGER N, LDZ, INFO
DOUBLE PRECISION AP(*), W(*), Z(LDZ,*), WORK(*)

SUBROUTINE DSPEV_64(JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, INFO)

CHARACTER*1 JOBZ, UPLO
INTEGER*8 N, LDZ, INFO
DOUBLE PRECISION AP(*), W(*), Z(LDZ,*), WORK(*)




F95 INTERFACE
SUBROUTINE SPEV(JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, INFO)

CHARACTER(LEN=1) :: JOBZ, UPLO
INTEGER :: N, LDZ, INFO
REAL(8), DIMENSION(:) :: AP, W, WORK
REAL(8), DIMENSION(:,:) :: Z

SUBROUTINE SPEV_64(JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, INFO)

CHARACTER(LEN=1) :: JOBZ, UPLO
INTEGER(8) :: N, LDZ, INFO
REAL(8), DIMENSION(:) :: AP, W, WORK
REAL(8), DIMENSION(:,:) :: Z




C INTERFACE
#include <sunperf.h>

void dspev(char jobz, char uplo, int n, double *ap, double  *w,  double
*z, int ldz, int *info);

void dspev_64(char jobz, char uplo, long n, double *ap, double *w, dou-
ble *z, long ldz, long *info);

Description

Oracle Solaris Studio Performance Library                            dspev(3P)



NAME
       dspev  - compute all the eigenvalues and, optionally, eigenvectors of a
       real symmetric matrix A in packed storage


SYNOPSIS
       SUBROUTINE DSPEV(JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, INFO)

       CHARACTER*1 JOBZ, UPLO
       INTEGER N, LDZ, INFO
       DOUBLE PRECISION AP(*), W(*), Z(LDZ,*), WORK(*)

       SUBROUTINE DSPEV_64(JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, INFO)

       CHARACTER*1 JOBZ, UPLO
       INTEGER*8 N, LDZ, INFO
       DOUBLE PRECISION AP(*), W(*), Z(LDZ,*), WORK(*)




   F95 INTERFACE
       SUBROUTINE SPEV(JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, INFO)

       CHARACTER(LEN=1) :: JOBZ, UPLO
       INTEGER :: N, LDZ, INFO
       REAL(8), DIMENSION(:) :: AP, W, WORK
       REAL(8), DIMENSION(:,:) :: Z

       SUBROUTINE SPEV_64(JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, INFO)

       CHARACTER(LEN=1) :: JOBZ, UPLO
       INTEGER(8) :: N, LDZ, INFO
       REAL(8), DIMENSION(:) :: AP, W, WORK
       REAL(8), DIMENSION(:,:) :: Z




   C INTERFACE
       #include <sunperf.h>

       void dspev(char jobz, char uplo, int n, double *ap, double  *w,  double
                 *z, int ldz, int *info);

       void dspev_64(char jobz, char uplo, long n, double *ap, double *w, dou-
                 ble *z, long ldz, long *info);



PURPOSE
       dspev computes all the eigenvalues and, optionally, eigenvectors  of  a
       real symmetric matrix A in packed storage.


ARGUMENTS
       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.


       AP (input/output)
                 Double  precision  array, dimension (N*(N+1)/2) On entry, the
                 upper or lower triangle of the  symmetric  matrix  A,  packed
                 columnwise in a linear array.  The j-th column of A is stored
                 in the array AP as follows: if UPLO = 'U', AP(i +  (j-1)*j/2)
                 =  A(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2)
                 = A(i,j) for j<=i<=n.

                 On exit, AP is overwritten by  values  generated  during  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 diag-
                 onal and first subdiagonal of T overwrite  the  corresponding
                 elements of A.


       W (output)
                 Double precision array, dimension (N) If INFO = 0, the eigen-
                 values in ascending order.


       Z (output)
                 Double precision 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 eigenvec-
                 tor  associated with W(i).  If JOBZ = 'N', then Z is not ref-
                 erenced.


       LDZ (input)
                 The leading dimension of the array Z.  LDZ >= 1, and if  JOBZ
                 = 'V', LDZ >= max(1,N).


       WORK (workspace)
                 Double precision array, dimension(3*N)

       INFO (output)
                 = 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 an intermediate tridiagonal form did not
                 converge to zero.




                                  7 Nov 2015                         dspev(3P)