U. If JOBU = 'U' or
          JOBU = 'I', LDU &gt;= MAX(1,N); if JOBU = 'N', LDU &gt;= 1.

</PRE>
<B>Workspace</B>
<PRE>
  DWORK   DOUBLE PRECISION array, dimension (MAX(N,P-1))

</PRE>
<B>Error Indicator</B>
<PRE>
  INFO    INTEGER
          = 0:  successful exit;
          &lt; 0:  if INFO = -i, the i-th argument had an illegal
                value.

</PRE>
<A name="Method"><B><FONT SIZE="+1">Method</FONT></B></A>
<PRE>
  The routine computes a unitary state-space transformation U, which
  reduces the pa