sgebak (3p)

Name

sgebak - form the right or left eigenvectors of a real general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by SGEBAL

Synopsis

SUBROUTINE SGEBAK(JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO)

CHARACTER*1 JOB, SIDE
INTEGER N, ILO, IHI, M, LDV, INFO
REAL SCALE(*), V(LDV,*)

SUBROUTINE SGEBAK_64(JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO)

CHARACTER*1 JOB, SIDE
INTEGER*8 N, ILO, IHI, M, LDV, INFO
REAL SCALE(*), V(LDV,*)




F95 INTERFACE
SUBROUTINE GEBAK(JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV,
INFO)

CHARACTER(LEN=1) :: JOB, SIDE
INTEGER :: N, ILO, IHI, M, LDV, INFO
REAL, DIMENSION(:) :: SCALE
REAL, DIMENSION(:,:) :: V

SUBROUTINE GEBAK_64(JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV,
INFO)

CHARACTER(LEN=1) :: JOB, SIDE
INTEGER(8) :: N, ILO, IHI, M, LDV, INFO
REAL, DIMENSION(:) :: SCALE
REAL, DIMENSION(:,:) :: V




C INTERFACE
#include <sunperf.h>

void sgebak(char job, char side, int n, int ilo, int ihi, float *scale,
int m, float *v, int ldv, int *info);

void sgebak_64(char job, char side, long n, long ilo, long  ihi,  float
*scale, long m, float *v, long ldv, long *info);

Description

Oracle Solaris Studio Performance Library                           sgebak(3P)



NAME
       sgebak  -  form the right or left eigenvectors of a real general matrix
       by backward transformation on the computed eigenvectors of the balanced
       matrix output by SGEBAL


SYNOPSIS
       SUBROUTINE SGEBAK(JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO)

       CHARACTER*1 JOB, SIDE
       INTEGER N, ILO, IHI, M, LDV, INFO
       REAL SCALE(*), V(LDV,*)

       SUBROUTINE SGEBAK_64(JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO)

       CHARACTER*1 JOB, SIDE
       INTEGER*8 N, ILO, IHI, M, LDV, INFO
       REAL SCALE(*), V(LDV,*)




   F95 INTERFACE
       SUBROUTINE GEBAK(JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV,
              INFO)

       CHARACTER(LEN=1) :: JOB, SIDE
       INTEGER :: N, ILO, IHI, M, LDV, INFO
       REAL, DIMENSION(:) :: SCALE
       REAL, DIMENSION(:,:) :: V

       SUBROUTINE GEBAK_64(JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV,
              INFO)

       CHARACTER(LEN=1) :: JOB, SIDE
       INTEGER(8) :: N, ILO, IHI, M, LDV, INFO
       REAL, DIMENSION(:) :: SCALE
       REAL, DIMENSION(:,:) :: V




   C INTERFACE
       #include <sunperf.h>

       void sgebak(char job, char side, int n, int ilo, int ihi, float *scale,
                 int m, float *v, int ldv, int *info);

       void sgebak_64(char job, char side, long n, long ilo, long  ihi,  float
                 *scale, long m, float *v, long ldv, long *info);



PURPOSE
       sgebak forms the right or left eigenvectors of a real general matrix by
       backward transformation on the computed eigenvectors  of  the  balanced
       matrix output by SGEBAL.


ARGUMENTS
       JOB (input)
                 Specifies  the  type  of  backward transformation required: =
                 'N', do nothing,  return  immediately;  =  'P',  do  backward
                 transformation  for  permutation  only;  =  'S',  do backward
                 transformation for scaling only; = 'B', do backward transfor-
                 mations  for  both  permutation and scaling.  JOB must be the
                 same as the argument JOB supplied to SGEBAL.


       SIDE (input)
                 = 'R':  V contains right eigenvectors;
                 = 'L':  V contains left eigenvectors.


       N (input) The number of rows of the matrix V.  N >= 0.


       ILO (input)
                 The integers ILO and IHI determined by SGEBAL.  1 <=  ILO  <=
                 IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.


       IHI (input)
                 See the description for ILO.


       SCALE (input)
                 Details  of  the permutation and scaling factors, as returned
                 by SGEBAL.


       M (input) The number of columns of the matrix V.  M >= 0.


       V (input/output)
                 On entry, the matrix of right  or  left  eigenvectors  to  be
                 transformed,  as returned by SHSEIN or STREVC.  On exit, V is
                 overwritten by the transformed eigenvectors.


       LDV (input)
                 The leading dimension of the array V. LDV >= max(1,N).


       INFO (output)
                 = 0:  successful exit
                 < 0:  if INFO = -i, the i-th argument had an illegal value.




                                  7 Nov 2015                        sgebak(3P)