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

.in +1c
.ti -1c
.RI "subroutine \fBdggbak\fP (job, side, n, ilo, ihi, lscale, rscale, m, v, ldv, info)"
.br
.RI "\fBDGGBAK\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "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)"

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

.PP
.nf
 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\&.
.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 DGGBAL\&.
.fi
.PP
.br
\fISIDE\fP 
.PP
.nf
          SIDE is CHARACTER*1
          = 'R':  V contains right eigenvectors;
          = 'L':  V contains left eigenvectors\&.
.fi
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.br
\fIN\fP 
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.nf
          N is INTEGER
          The number of rows of the matrix V\&.  N >= 0\&.
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.PP
.br
\fIILO\fP 
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.nf
          ILO is INTEGER
.fi
.PP
.br
\fIIHI\fP 
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.nf
          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\&.
.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 DGGBAL\&.
.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 DGGBAL\&.
.fi
.PP
.br
\fIM\fP 
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          M is INTEGER
          The number of columns of the matrix V\&.  M >= 0\&.
.fi
.PP
.br
\fIV\fP 
.PP
.nf
          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\&.
.fi
.PP
.br
\fILDV\fP 
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.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 
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Univ\&. of Colorado Denver 
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NAG Ltd\&. 
.RE
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\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 \fB145\fP of file \fBdggbak\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.