SRC/cggbak.f(3) Library Functions Manual SRC/cggbak.f(3) NAME SRC/cggbak.f SYNOPSIS Functions/Subroutines subroutine cggbak (job, side, n, ilo, ihi, lscale, rscale, m, v, ldv, info) CGGBAK Function/Subroutine Documentation subroutine cggbak (character job, character side, integer n, integer ilo, integer ihi, real, dimension( * ) lscale, real, dimension( * ) rscale, integer m, complex, dimension( ldv, * ) v, integer ldv, integer info) CGGBAK Purpose: !> !> CGGBAK forms the right or left eigenvectors of a complex generalized !> eigenvalue problem A*x = lambda*B*x, by backward transformation on !> the computed eigenvectors of the balanced pair of matrices output by !> CGGBAL. !> 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 CGGBAL. !> 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 CGGBAL. !> 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0. !> LSCALE !> LSCALE is REAL array, dimension (N) !> Details of the permutations and/or scaling factors applied !> to the left side of A and B, as returned by CGGBAL. !> RSCALE !> RSCALE is REAL array, dimension (N) !> Details of the permutations and/or scaling factors applied !> to the right side of A and B, as returned by CGGBAL. !> 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 CTGEVC. !> 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 146 of file cggbak.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 SRC/cggbak.f(3)