--- a/src/expression.h	Mon Jul 15 17:00:16 2013 +0200
+++ b/src/expression.h	Mon Jul 15 17:02:28 2013 +0200
@@ -30,23 +30,25 @@
 {
 
  public:
+  expression() : dolfin::Expression() {}
+
   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;
+    b.resize (xy.size ());
+    for (int i = 0; i < xy.size (); ++i)
+      b(i) = xy[i];
     octave_value_list res = feval (f->function_value (), b);
     values[0] = res(0).double_value ();
   }
 
+ private:
   octave_fcn_handle * f;
 };