D'), 0 &lt;= ALPHA &lt;= 1 represents the
          boundary value for the moduli of eigenvalues.
          The ALPHA-stability domain does not include the boundary.

  BETA    (input) DOUBLE PRECISION
          BETA &gt; 0 specifies the absolute/relative error weighting
          parameter. A large positive value of BETA favours the
          minimization of the absolute approximation error, while a
          small value of BETA is appropriate for the minimization
          of the relative error.
         