COMHES(3F)

NAME
     COMHES, SCOMHES  -  EISPACK routine.  Given a COMPLEX GENERAL matrix,
     this subroutine reduces a submatrix situated in rows and columns LOW
     through IGH to upper Hessenberg form by stabilized elementary similarity
     transformations.


SYNOPSYS
          subroutine  comhes(nm, n, low, igh, ar, ai, int)
          integer          nm, n, low, igh
          double precision ar(nm,n), ai(nm,n)
          integer          int(igh)

          subroutine scomhes(nm, n, low, igh, ar, ai, int)
          integer          nm, n, low, igh
          real             ar(nm,n), ai(nm,n)
          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.

     N is the order of the matrix.

     LOW and IGH ARE integers determined by the balancing subroutine  CBAL.
     If  CBAL  has not been used, set LOW=1, IGH=N.

     AR and AI contain the real and imaginary parts, respectively, of the
     complex input matrix.  On OUTPUT

     AR and AI contain the real and imaginary parts, respectively, of the
     Hessenberg matrix.  The multipliers which were used in the reduction are
     stored in the remaining triangles under the Hessenberg matrix.

     INT contains information on the rows and columns interchanged in the
     reduction.  Only elements LOW through IGH are used.  Calls CDIV for
     complex division.  Questions and comments should be directed to B. S.
     Garbow, APPLIED MATHEMATICS DIVISION, ARGONNE NATIONAL LABORATORY