COMLR(3F)

NAME
     COMLR, SCOMLR   -  EISPACK routine.  This subroutine finds the
     eigenvalues of a COMPLEX UPPER Hessenberg matrix by the modified LR
     method.


SYNOPSYS
          subroutine  comlr(nm, n, low, igh, hr, hi, wr, wi, ierr)
          integer          nm, n, low, igh, ierr
          double precision hr(nm,n), hi(nm,n), wr(n), wi(n)

          subroutine scomlr(nm, n, low, igh, hr, hi, wr, wi, ierr)
          integer          nm, n, low, igh, ierr
          real             hr(nm,n), hi(nm,n), wr(n), wi(n)



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.

     HR and HI contain the real and imaginary parts, respectively, of the
     complex upper Hessenberg matrix.  Their lower triangles below the
     subdiagonal contain the multipliers which were used in the reduction by
     COMHES, if performed.  On OUTPUT The upper Hessenberg portions of HR and
     HI have been destroyed.  Therefore, they must be saved before calling
     COMLR  if subsequent calculation of eigenvectors is to be performed.

     WR and WI contain the real and imaginary parts, respectively, of the
     eigenvalues.  If an error exit is made, the eigenvalues should be correct
     for indices IERR+1,...,N.

     IERR is set to Zero       for normal return, J          if the J-th
     eigenvalue has not been
        determined after a total of 30*N iterations.  Calls CSROOT for complex
     square root.  Calls CDIV for complex division.  Questions and comments
     should be directed to B. S. Garbow, APPLIED MATHEMATICS DIVISION, ARGONNE
     NATIONAL LABORATORY