ZGEBAK
November 2006
Purpose
ZGEBAK forms the right or left eigenvectors of a complex general
matrix by backward transformation on the computed eigenvectors of the
balanced matrix output by ZGEBAL.
matrix by backward transformation 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 i-th argument had an illegal value. |