SRC/dggbak.f(3)            Library Functions Manual            SRC/dggbak.f(3)

NAME
       SRC/dggbak.f

SYNOPSIS
   Functions/Subroutines
       subroutine dggbak (job, side, n, ilo, ihi, lscale, rscale, m, v, ldv,
           info)
           DGGBAK

Function/Subroutine Documentation
   subroutine dggbak (character job, character side, integer n, integer ilo,
       integer ihi, double precision, dimension( * ) lscale, double precision,
       dimension( * ) rscale, integer m, double precision, dimension( ldv, * )
       v, integer ldv, integer info)
       DGGBAK

       Purpose:


           !>
           !> DGGBAK forms the right or left eigenvectors of a real generalized
           !> eigenvalue problem A*x = lambda*B*x, by backward transformation on
           !> the computed eigenvectors of the balanced pair of matrices output by
           !> DGGBAL.
           !>

       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 DGGBAL.
           !>

           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 DGGBAL.
           !>          1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
           !>

           LSCALE

           !>          LSCALE is DOUBLE PRECISION array, dimension (N)
           !>          Details of the permutations and/or scaling factors applied
           !>          to the left side of A and B, as returned by DGGBAL.
           !>

           RSCALE

           !>          RSCALE is DOUBLE PRECISION array, dimension (N)
           !>          Details of the permutations and/or scaling factors applied
           !>          to the right side of A and B, as returned by DGGBAL.
           !>

           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 DTGEVC.
           !>          On exit, V is overwritten by the transformed eigenvectors.
           !>

           LDV

           !>          LDV is INTEGER
           !>          The leading dimension of the matrix 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.

       Further Details:


           !>
           !>  See R.C. Ward, Balancing the generalized eigenvalue problem,
           !>                 SIAM J. Sci. Stat. Comp. 2 (1981), 141-152.
           !>

       Definition at line 145 of file dggbak.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/dggbak.f(3)