gebak(3)

NAME
gebak - gebak: back-transform eigvec

SYNOPSIS

  Functions
subroutine cgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info)
CGEBAK
subroutine dgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info)
DGEBAK
subroutine sgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info)
SGEBAK
subroutine zgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info)
ZGEBAK

Detailed Description

Function Documentation

  subroutine cgebak (character job, character side, integer n, integer ilo, integer ihi, real, dimension( * ) scale, integer m, complex, dimension( ldv, * ) v, integer ldv, integer info)

CGEBAK

Purpose:

     CGEBAK forms the right or left eigenvectors of a complex general
     matrix by backward transformation on the computed eigenvectors of the
     balanced matrix output by CGEBAL.

Parameters
    JOB

              JOB is CHARACTER*1
              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 transformations for both permutation and
                     scaling.
              JOB must be the same as the argument JOB supplied to CGEBAL.

    SIDE

              SIDE is CHARACTER*1
              = 'R':  V contains right eigenvectors;
              = 'L':  V contains left eigenvectors.

    N

              N is INTEGER
              The number of rows of the matrix V.  N >= 0.

    ILO

              ILO is INTEGER

    IHI

              IHI is INTEGER
              The integers ILO and IHI determined by CGEBAL.
              1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

    SCALE

              SCALE is REAL array, dimension (N)
              Details of the permutation and scaling factors, as returned
              by CGEBAL.

    M

              M is INTEGER
              The number of columns of the matrix V.  M >= 0.

    V

              V is COMPLEX array, dimension (LDV,M)
              On entry, the matrix of right or left eigenvectors to be
              transformed, as returned by CHSEIN or CTREVC.
              On exit, V is overwritten by the transformed eigenvectors.

    LDV

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

    INFO

              INFO is INTEGER
              = 0:  successful exit
              < 0:  if INFO = -i, the i-th argument had an illegal value.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 129 of file cgebak.f.

  subroutine dgebak (character job, character side, integer n, integer ilo, integer ihi, double precision, dimension( * ) scale, integer m, double precision, dimension( ldv, * ) v, integer ldv, integer info)

DGEBAK

Purpose:

     DGEBAK forms the right or left eigenvectors of a real general matrix
     by backward transformation on the computed eigenvectors of the
     balanced matrix output by DGEBAL.

Parameters
    JOB

              JOB is CHARACTER*1
              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 transformations for both permutation and
                     scaling.
              JOB must be the same as the argument JOB supplied to DGEBAL.

    SIDE

              SIDE is CHARACTER*1
              = 'R':  V contains right eigenvectors;
              = 'L':  V contains left eigenvectors.

    N

              N is INTEGER
              The number of rows of the matrix V.  N >= 0.

    ILO

              ILO is INTEGER

    IHI

              IHI is INTEGER
              The integers ILO and IHI determined by DGEBAL.
              1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

    SCALE

              SCALE is DOUBLE PRECISION array, dimension (N)
              Details of the permutation and scaling factors, as returned
              by DGEBAL.

    M

              M is INTEGER
              The number of columns of the matrix V.  M >= 0.

    V

              V is DOUBLE PRECISION array, dimension (LDV,M)
              On entry, the matrix of right or left eigenvectors to be
              transformed, as returned by DHSEIN or DTREVC.
              On exit, V is overwritten by the transformed eigenvectors.

    LDV

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

    INFO

              INFO is INTEGER
              = 0:  successful exit
              < 0:  if INFO = -i, the i-th argument had an illegal value.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 128 of file dgebak.f.

  subroutine sgebak (character job, character side, integer n, integer ilo, integer ihi, real, dimension( * ) scale, integer m, real, dimension( ldv, * ) v, integer ldv, integer info)

SGEBAK

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.

Parameters
    JOB

              JOB is CHARACTER*1
              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 transformations for both permutation and
                     scaling.
              JOB must be the same as the argument JOB supplied to SGEBAL.

    SIDE

              SIDE is CHARACTER*1
              = 'R':  V contains right eigenvectors;
              = 'L':  V contains left eigenvectors.

    N

              N is INTEGER
              The number of rows of the matrix V.  N >= 0.

    ILO

              ILO is INTEGER

    IHI

              IHI is INTEGER
              The integers ILO and IHI determined by SGEBAL.
              1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

    SCALE

              SCALE is REAL array, dimension (N)
              Details of the permutation and scaling factors, as returned
              by SGEBAL.

    M

              M is INTEGER
              The number of columns of the matrix V.  M >= 0.

    V

              V is REAL array, dimension (LDV,M)
              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

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

    INFO

              INFO is INTEGER
              = 0:  successful exit
              < 0:  if INFO = -i, the i-th argument had an illegal value.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 128 of file sgebak.f.

  subroutine zgebak (character job, character side, integer n, integer ilo, integer ihi, double precision, dimension( * ) scale, integer m, complex*16, dimension( ldv, * ) v, integer ldv, integer info)

ZGEBAK

Purpose:

     ZGEBAK forms the right or left eigenvectors of a complex general
     matrix by backward transformation on the computed eigenvectors of the
     balanced matrix output by ZGEBAL.

Parameters
    JOB

              JOB is CHARACTER*1
              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 transformations for both permutation and
                     scaling.
              JOB must be the same as the argument JOB supplied to ZGEBAL.

    SIDE

              SIDE is CHARACTER*1
              = 'R':  V contains right eigenvectors;
              = 'L':  V contains left eigenvectors.

    N

              N is INTEGER
              The number of rows of the matrix V.  N >= 0.

    ILO

              ILO is INTEGER

    IHI

              IHI is INTEGER
              The integers ILO and IHI determined by ZGEBAL.
              1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

    SCALE

              SCALE is DOUBLE PRECISION array, dimension (N)
              Details of the permutation and scaling factors, as returned
              by ZGEBAL.

    M

              M is INTEGER
              The number of columns of the matrix V.  M >= 0.

    V

              V is COMPLEX*16 array, dimension (LDV,M)
              On entry, the matrix of right or left eigenvectors to be
              transformed, as returned by ZHSEIN or ZTREVC.
              On exit, V is overwritten by the transformed eigenvectors.

    LDV

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

    INFO

              INFO is INTEGER
              = 0:  successful exit
              < 0:  if INFO = -i, the i-th argument had an illegal value.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 129 of file zgebak.f.

Author

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