.TH "SRC/zggbak.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/zggbak.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBzggbak\fP (job, side, n, ilo, ihi, lscale, rscale, m, v, ldv, info)"
.br
.RI "\fBZGGBAK\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine zggbak (character job, character side, integer n, integer ilo, integer ihi, double precision, dimension( * ) lscale, double precision, dimension( * ) rscale, integer m, complex*16, dimension( ldv, * ) v, integer ldv, integer info)"

.PP
\fBZGGBAK\fP  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
!>
!> ZGGBAK 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
!> ZGGBAL\&.
!> 
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIJOB\fP 
.PP
.nf
!>          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 ZGGBAL\&.
!> 
.fi
.PP
.br
\fISIDE\fP 
.PP
.nf
!>          SIDE is CHARACTER*1
!>          = 'R':  V contains right eigenvectors;
!>          = 'L':  V contains left eigenvectors\&.
!> 
.fi
.PP
.br
\fIN\fP 
.PP
.nf
!>          N is INTEGER
!>          The number of rows of the matrix V\&.  N >= 0\&.
!> 
.fi
.PP
.br
\fIILO\fP 
.PP
.nf
!>          ILO is INTEGER
!> 
.fi
.PP
.br
\fIIHI\fP 
.PP
.nf
!>          IHI is INTEGER
!>          The integers ILO and IHI determined by ZGGBAL\&.
!>          1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0\&.
!> 
.fi
.PP
.br
\fILSCALE\fP 
.PP
.nf
!>          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 ZGGBAL\&.
!> 
.fi
.PP
.br
\fIRSCALE\fP 
.PP
.nf
!>          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 ZGGBAL\&.
!> 
.fi
.PP
.br
\fIM\fP 
.PP
.nf
!>          M is INTEGER
!>          The number of columns of the matrix V\&.  M >= 0\&.
!> 
.fi
.PP
.br
\fIV\fP 
.PP
.nf
!>          V is COMPLEX*16 array, dimension (LDV,M)
!>          On entry, the matrix of right or left eigenvectors to be
!>          transformed, as returned by ZTGEVC\&.
!>          On exit, V is overwritten by the transformed eigenvectors\&.
!> 
.fi
.PP
.br
\fILDV\fP 
.PP
.nf
!>          LDV is INTEGER
!>          The leading dimension of the matrix V\&. LDV >= max(1,N)\&.
!> 
.fi
.PP
.br
\fIINFO\fP 
.PP
.nf
!>          INFO is INTEGER
!>          = 0:  successful exit\&.
!>          < 0:  if INFO = -i, the i-th argument had an illegal value\&.
!> 
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 

.PP
Univ\&. of California Berkeley 

.PP
Univ\&. of Colorado Denver 

.PP
NAG Ltd\&. 
.RE
.PP
\fBFurther Details:\fP
.RS 4

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

.PP
Definition at line \fB146\fP of file \fBzggbak\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.