sgebak.f man page

sgebak.f —

Synopsis

Functions/Subroutines

subroutine sgebak (JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO)
SGEBAK

Function/Subroutine Documentation

subroutine sgebak (characterJOB, characterSIDE, integerN, integerILO, integerIHI, real, dimension( * )SCALE, integerM, real, dimension( ldv, * )V, integerLDV, integerINFO)

SGEBAK

Purpose:

SGEBAK forms the right or left eigenvectors of a real general matrix
by backward transformation on the computed eigenvectors of the
balanced matrix output by SGEBAL.

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 SGEBAL.

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 SGEBAL.
1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

SCALE

SCALE is REAL array, dimension (N)
Details of the permutation and scaling factors, as returned
by SGEBAL.

M

M is INTEGER
The number of columns of the matrix V.  M >= 0.

V

V is REAL array, dimension (LDV,M)
On entry, the matrix of right or left eigenvectors to be
transformed, as returned by SHSEIN or STREVC.
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 sgebak.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

Sat Nov 16 2013 Version 3.4.2 LAPACK