added permeability function to problem to plot kappa

mlmc/src/problems/StochasticEllipticProblem.hpp

@@ -17,10 +17,10 @@ public:
 
   virtual Tensor Permeability(const cell &c) const = 0;
 
-//  void Permeability(Vector &kappa) {
-//    for (cell c = kappa.cells(); c != kappa.cells_end(); ++c)
-//      Permeability(c);
-//  }
+  void Permeability(Vector &kappa) {
+    for (cell c = kappa.cells(); c != kappa.cells_end(); ++c)
+      kappa(c(), 0) = Permeability(c)[0][0];
+  }
 };
 
 class StochasticLaplace1D : public IStochasticEllipticProblem {