1CGEBAK(1)                LAPACK routine (version 3.2)                CGEBAK(1)
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NAME

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

11       SUBROUTINE CGEBAK( 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           REAL           SCALE( * )
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19           COMPLEX        V( LDV, * )
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PURPOSE

22       CGEBAK 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 CGEBAL.
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ARGUMENTS

27       JOB     (input) CHARACTER*1
28               Specifies  the type of backward transformation required: = 'N',
29               do nothing, return immediately; = 'P', do backward  transforma‐
30               tion  for  permutation  only; = 'S', do backward transformation
31               for scaling only; = 'B', do backward transformations  for  both
32               permutation  and scaling.  JOB must be the same as the argument
33               JOB supplied to CGEBAL.
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35       SIDE    (input) CHARACTER*1
36               = 'R':  V contains right eigenvectors;
37               = 'L':  V contains left eigenvectors.
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39       N       (input) INTEGER
40               The number of rows of the matrix V.  N >= 0.
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42       ILO     (input) INTEGER
43               IHI     (input) INTEGER The integers ILO and IHI determined  by
44               CGEBAL.   1  <=  ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if
45               N=0.
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47       SCALE   (input) REAL array, dimension (N)
48               Details of the permutation and scaling factors, as returned  by
49               CGEBAL.
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51       M       (input) INTEGER
52               The number of columns of the matrix V.  M >= 0.
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54       V       (input/output) COMPLEX array, dimension (LDV,M)
55               On entry, the matrix of right or left eigenvectors to be trans‐
56               formed, as returned by CHSEIN or CTREVC.  On exit, V  is  over‐
57               written by the transformed eigenvectors.
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59       LDV     (input) INTEGER
60               The leading dimension of the array V. LDV >= max(1,N).
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62       INFO    (output) INTEGER
63               = 0:  successful exit
64               < 0:  if INFO = -i, the i-th argument had an illegal value.
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68 LAPACK routine (version 3.2)    November 2008                       CGEBAK(1)
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