diff --git a/dune/faultnetworks/faultfactories/cantorfaultfactory.hh b/dune/faultnetworks/faultfactories/cantorfaultfactory.hh
index 2b4e84a7a5e7aa8f4d2faad6114da8310959bf2f..6ec462732dc352df619adcf344ca9e4066bc9ee6 100644
--- a/dune/faultnetworks/faultfactories/cantorfaultfactory.hh
+++ b/dune/faultnetworks/faultfactories/cantorfaultfactory.hh
@@ -11,6 +11,7 @@
 #include <dune/grid/common/mcmgmapper.hh>
 
 
+// levelinterfacenetwork -> midpoints of edges -> constructs and stores its index coordinates  
 class CantorIndexHierarchy {
 	public:
 		typedef std::map<std::pair<int,int>, bool> LevelCantorIndices;
@@ -100,7 +101,7 @@ class CantorFaultFactory
 
     protected:
         typedef OscUnitCube<GridType, 2> GridOb;
-        static const int dimworld = GridType::dimensionworld ;
+        static const int dimworld = GridType::dimensionworld;
         static const int dim = GridType::dimension;
         typedef typename GridType::ctype ctype;
         typedef typename GridType::LevelGridView GV;
diff --git a/dune/faultnetworks/faultfactories/rockfaultfactory.hh b/dune/faultnetworks/faultfactories/rockfaultfactory.hh
index ed50053d9e50d1a223d5c1e37f396d6d39b2a1e4..bb2dd27cb63d3e03b1a84ca1049b49df80c41c14 100644
--- a/dune/faultnetworks/faultfactories/rockfaultfactory.hh
+++ b/dune/faultnetworks/faultfactories/rockfaultfactory.hh
@@ -504,22 +504,30 @@ protected:
                 auto bottom = vertexPositions_[newRock.bottom];
 
                 MyRock rock00;
-                auto center00 = 1.0/2*(right + bottom);
+                auto center00 = right;
+		center00 += bottom;
+		center00 *= 1.0/2;
                 createRock(rock00, center00, separatingDofs, x2Fault->getInterfaceDofs(), 0, y1Fault->getInterfaceDofs(), 0);
                 rocks_.push_back(rock00);
 
                 MyRock rock01;
-                auto center01 = 1.0/2*(left + bottom);
+                auto center01 = left;
+		center01 += bottom;
+		center01 *= 1.0/2;
                 createRock(rock01, center01, separatingDofs, x1Fault->getInterfaceDofs(), 0, y1Fault->getInterfaceDofs(), 1);
                 rocks_.push_back(rock01);
 
                 MyRock rock10;
-                auto center10 = 1.0/2*(right + top);
+                auto center10 = right;
+		center10 += top;
+		center10 *= 1.0/2;
                 createRock(rock10, center10, separatingDofs, x2Fault->getInterfaceDofs(), 1, y2Fault->getInterfaceDofs(), 0);
                 rocks_.push_back(rock10);
 
                 MyRock rock11;
-                auto center11 = 1.0/2*(left + top);
+                auto center11 = left;
+		center11 += top;
+		center11 *= 1.0/2;
                 createRock(rock11, center11, separatingDofs, x1Fault->getInterfaceDofs(), 1, y2Fault->getInterfaceDofs(), 1);
                 rocks_.push_back(rock11);
             }