1ZGEBAK(1)                LAPACK routine (version 3.1)                ZGEBAK(1)
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NAME

6       ZGEBAK  - the right or left eigenvectors of a complex general matrix by
7       backward transformation on the computed eigenvectors  of  the  balanced
8       matrix output by ZGEBAL
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SYNOPSIS

11       SUBROUTINE ZGEBAK( JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO )
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13           CHARACTER      JOB, SIDE
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15           INTEGER        IHI, ILO, INFO, LDV, M, N
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17           DOUBLE         PRECISION SCALE( * )
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19           COMPLEX*16     V( LDV, * )
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PURPOSE

22       ZGEBAK forms the right or left eigenvectors of a complex general matrix
23       by backward transformation on the computed eigenvectors of the balanced
24       matrix output by ZGEBAL.
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ARGUMENTS

28       JOB     (input) CHARACTER*1
29               Specifies  the type of backward transformation required: = 'N',
30               do nothing, return immediately; = 'P', do backward  transforma‐
31               tion  for  permutation  only; = 'S', do backward transformation
32               for scaling only; = 'B', do backward transformations  for  both
33               permutation  and scaling.  JOB must be the same as the argument
34               JOB supplied to ZGEBAL.
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36       SIDE    (input) CHARACTER*1
37               = 'R':  V contains right eigenvectors;
38               = 'L':  V contains left eigenvectors.
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40       N       (input) INTEGER
41               The number of rows of the matrix V.  N >= 0.
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43       ILO     (input) INTEGER
44               IHI     (input) INTEGER The integers ILO and IHI determined  by
45               ZGEBAL.   1  <=  ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if
46               N=0.
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48       SCALE   (input) DOUBLE PRECISION array, dimension (N)
49               Details of the permutation and scaling factors, as returned  by
50               ZGEBAL.
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52       M       (input) INTEGER
53               The number of columns of the matrix V.  M >= 0.
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55       V       (input/output) COMPLEX*16 array, dimension (LDV,M)
56               On entry, the matrix of right or left eigenvectors to be trans‐
57               formed, as returned by ZHSEIN or ZTREVC.  On exit, V  is  over‐
58               written by the transformed eigenvectors.
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60       LDV     (input) INTEGER
61               The leading dimension of the array V. LDV >= max(1,N).
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63       INFO    (output) INTEGER
64               = 0:  successful exit
65               < 0:  if INFO = -i, the i-th argument had an illegal value.
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69 LAPACK routine (version 3.1)    November 2006                       ZGEBAK(1)
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