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 (characterJOB, characterSIDE, integerN, integerILO, integerIHI, double precision, dimension( * )SCALE, integerM, double precision, dimension( ldv, * )V, integerLDV, integerINFO)

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

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Definition at line 130 of file dgebak.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dgebak(3) is an alias of dgebak.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK