Added catch for which g integration to use, incomplete, does not yet include point sources such as for DC.

src/FEM4EllipticPDE.cpp

     void FEM4EllipticPDE::Solve( const std::string& resfile ) {
         ConstructAMatrix();
         //SetupLineSourcePotential();
-        SetupSurfaceSourcePotential();
-        //SetupPotential();
+
+        if (vtkGrid->GetPointData()->GetScalars("G") ) {
+            SetupSurfaceSourcePotential();
+        } else if (vtkGrid->GetCellData()->GetScalars("G") ) {
+            SetupPotential();
+        }
+
+
         //ConstructLoadVector();
 
         std::cout << "\nSolving" << std::endl;