cgebak (l)  Linux Manuals
cgebak: forms the right or left eigenvectors of a complex general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by CGEBAL
Command to display cgebak
manual in Linux: $ man l cgebak
NAME
CGEBAK  forms the right or left eigenvectors of a complex general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by CGEBAL
SYNOPSIS
 SUBROUTINE CGEBAK(

JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV,
INFO )

CHARACTER
JOB, SIDE

INTEGER
IHI, ILO, INFO, LDV, M, N

REAL
SCALE( * )

COMPLEX
V( LDV, * )
PURPOSE
CGEBAK forms the right or left eigenvectors of a complex general
matrix by backward transformation on the computed eigenvectors of the
balanced matrix output by CGEBAL.
ARGUMENTS
 JOB (input) CHARACTER*1

Specifies the type of backward transformation required:
= aqNaq, do nothing, return immediately;
= aqPaq, do backward transformation for permutation only;
= aqSaq, do backward transformation for scaling only;
= aqBaq, do backward transformations for both permutation and
scaling.
JOB must be the same as the argument JOB supplied to CGEBAL.
 SIDE (input) CHARACTER*1

= aqRaq: V contains right eigenvectors;
= aqLaq: 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 CGEBAL.
1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
 SCALE (input) REAL array, dimension (N)

Details of the permutation and scaling factors, as returned
by CGEBAL.
 M (input) INTEGER

The number of columns of the matrix V. M >= 0.
 V (input/output) COMPLEX array, dimension (LDV,M)

On entry, the matrix of right or left eigenvectors to be
transformed, as returned by CHSEIN or CTREVC.
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.
Pages related to cgebak
 cgebak (3)
 cgebal (l)  balances a general complex matrix A
 cgebd2 (l)  reduces a complex general m by n matrix A to upper or lower real bidiagonal form B by a unitary transformation
 cgebrd (l)  reduces a general complex MbyN matrix A to upper or lower bidiagonal form B by a unitary transformation
 cgecon (l)  estimates the reciprocal of the condition number of a general complex matrix A, in either the 1norm or the infinitynorm, using the LU factorization computed by CGETRF
 cgeequ (l)  computes row and column scalings intended to equilibrate an MbyN matrix A and reduce its condition number
 cgeequb (l)  computes row and column scalings intended to equilibrate an MbyN matrix A and reduce its condition number
 cgees (l)  computes for an NbyN complex nonsymmetric matrix A, the eigenvalues, the Schur form T, and, optionally, the matrix of Schur vectors Z