
ZGEBAK(l) ) ZGEBAK(l)
NAME
ZGEBAK  form the right or left eigenvectors of a complex general matrix by backward
transformation on the computed eigenvectors of the balanced matrix output by ZGEBAL
SYNOPSIS
SUBROUTINE ZGEBAK( JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO )
CHARACTER JOB, SIDE
INTEGER IHI, ILO, INFO, LDV, M, N
DOUBLE PRECISION SCALE( * )
COMPLEX*16 V( LDV, * )
PURPOSE
ZGEBAK forms the right or left eigenvectors of a complex general matrix by backward trans
formation on the computed eigenvectors of the balanced matrix output by ZGEBAL.
ARGUMENTS
JOB (input) 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 ZGEBAL.
SIDE (input) CHARACTER*1
= 'R': V contains right eigenvectors;
= 'L': V contains left eigenvectors.
N (input) INTEGER
The number of rows of the matrix V. N >= 0.
ILO (input) INTEGER
IHI (input) INTEGER The integers ILO and IHI determined by ZGEBAL. 1 <= ILO
<= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
SCALE (input) DOUBLE PRECISION array, dimension (N)
Details of the permutation and scaling factors, as returned by ZGEBAL.
M (input) INTEGER
The number of columns of the matrix V. M >= 0.
V (input/output) COMPLEX*16 array, dimension (LDV,M)
On entry, the matrix of right or left eigenvectors to be transformed, as returned
by ZHSEIN or ZTREVC. On exit, V is overwritten by the transformed eigenvectors.
LDV (input) INTEGER
The leading dimension of the array V. LDV >= max(1,N).
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value.
LAPACK version 3.0 15 June 2000 ZGEBAK(l) 
