ng the equivalence transformation

     Dl*A*Dr and Dl*B*Dr.

  For THRESH = 0, the routine returns essentially the same results
  as the LAPACK subroutine DGGBAL [1]. Setting THRESH &lt; 0, usually
  gives better results than DGGBAL for badly scaled matrix pencils.

</PRE>
<A name="References"><B><FONT SIZE="+1">References</FONT></B></A>
<PRE>
  [1] Anderson, E., Bai, Z., Bischof, C., Demmel, J., Dongarra, J.,
      Du Croz, J., Greenbaum, A., Hammarling, S., McKenney, A.,
      Ostrouchov, S., and Sorense