--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/expression.h	Fri Jul 12 13:58:58 2013 +0200
@@ -0,0 +1,53 @@
+/*
+ Copyright (C) 2013 Marco Vassallo
+
+ This program is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 2 of the License, or (at your option) any later
+ version.
+
+ This program is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ details.
+
+ You should have received a copy of the GNU General Public License along with
+ this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _EXPRESSION_OCTAVE_
+#define _EXPRESSION_OCTAVE_
+
+#include <dolfin.h>
+#include <octave/oct.h>
+#include <octave/oct-map.h>
+#include <octave/ov-fcn-handle.h>
+#include <octave/ov-fcn.h>
+#include <octave/parse.h>
+#include <octave/octave.h>
+
+class expression : public dolfin::Expression
+{
+
+ public:
+  expression (octave_fcn_handle & _f) :
+             dolfin::Expression (), f (new octave_fcn_handle (_f)) {}
+
+  ~expression (void) { delete f; }
+
+  void eval (dolfin::Array<double>& values, const dolfin::Array<double>& xy) const
+  {
+    double x = xy[0];
+    double y = xy[1];
+    octave_value_list b;
+    b.resize (2);
+    b(0) = x;
+    b(1) = y;
+    octave_value_list res = feval (f->function_value (), b);
+    values[0] = res(0).double_value ();
+  }
+
+  octave_fcn_handle * f;
+};
+
+#endif