# dgebak.f man page

dgebak.f

## Synopsis

### Functions/Subroutines

subroutine dgebak (JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO)
DGEBAK

## Function/Subroutine Documentation

### 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

NAG Ltd.

Date:

December 2016

Definition at line 132 of file dgebak.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dgebak(3) is an alias of dgebak.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK