>Evaluation in particular polyhedra</b>
      <br><br>
 
 
      <tt>fval = U.feval(x, 'myfun', 'regions', indices)</tt> evaluates function
 <tt>myfun</tt> over all polyhedra indexed by <tt>indices</tt>. The output <tt>fval</tt> is
 always an <img src="../../../../../../fig/mpt/modules/geometry/unions/@PolyUnion/feval9.png" alt="../../../../../../fig/mpt/modules/geometry/unions/@PolyUnion/feval9.png"> matrix, where <img src="../../../../../../fig/mpt/modules/geometry/unions/@PolyUnion/feval10.png" alt="../.