_COMBAK(3F)_COMBAK(3F)NAME
COMBAK, SCOMBAK - EISPACK routine. This subroutine forms the
eigenvectors of a COMPLEX GENERAL matrix by back transforming those of
the corresponding upper Hessenberg matrix determined by COMHES.
SYNOPSYS
subroutine combak(nm, low, igh, ar, ai, int, m, zr, zi)
integer nm, low, igh, m
double precision ar(nm,igh),ai(nm,igh),zr(nm,m),zi(nm,m)
integer int(igh)
subroutine scombak(nm, low, igh, ar, ai, int, m, zr, zi)
integer nm, low, igh, m
real ar(nm,igh),ai(nm,igh),zr(nm,m),zi(nm,m)
integer int(igh)DESCRIPTION
On INPUT
NM must be set to the row dimension of two-dimensional array parameters
as declared in the calling program dimension statement.
LOW and IGH are integers determined by the balancing subroutine CBAL.
If CBAL has not been used, set LOW=1 and IGH equal to the order of the
matrix.
AR and AI contain the multipliers which were used in the reduction by
COMHES in their lower triangles below the subdiagonal.
INT contains information on the rows and columns interchanged in the
reduction by COMHES. Only elements LOW through IGH are used.
M is the number of eigenvectors to be back transformed.
ZR and ZI contain the real and imaginary parts, respectively, of the
eigenvectors to be back transformed in their first M columns. On OUTPUT
ZR and ZI contain the real and imaginary parts, respectively, of the
transformed eigenvectors in their first M columns. Questions and
comments should be directed to B. S. Garbow, APPLIED MATHEMATICS
DIVISION, ARGONNE NATIONAL LABORATORY
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