Merge branch 'feature/41-enable-vtk-vertex-plotting' into 'master'

Add new config key 'output.vertexData' for plotting vertex data

Closes #41

See merge request !21

doc/default_files/parameters.xml

@@ -50,6 +50,17 @@ adding an empty line, make text **bold** or ``monospaced``.
       <values> string </values>
     </parameter>
 
+    <parameter name="vertexData">
+      <definition> Plot vertex based (``true``) or cell-centered (``false``)
+       data into VTK files. Vertex based data might render sharp
+       parameterization boundaries inappropriately.
+       System tests and plotting functions (``dorie plot``) require
+       cell-centered data.
+      </definition>
+      <values> true, false </values>
+      <suggestion> false </suggestion>
+    </parameter>
+
     <parameter name="asciiVtk">
       <definition> Defines whether VTK files should be written as ASCII (``true``)
         or binary (``false``). ASCII is easier to parse in case you want to write

dune/dorie/interface/output.hh

@@ -77,11 +77,20 @@ public:
 		auto waterdgf_vtk = std::make_shared<Dune::PDELab::VTKGridFunctionAdapter<WaterDGF>>(waterdgf,"theta_w");
 		auto satdgf_vtk = std::make_shared<Dune::PDELab::VTKGridFunctionAdapter<SatDGF>>(satdgf,"Theta");
 
-		vtkwriter.addCellData(udgf_vtk);
-		vtkwriter.addCellData(fluxdgf_vtk);
-		vtkwriter.addCellData(condgf_vtk);
-		vtkwriter.addCellData(waterdgf_vtk);
-		vtkwriter.addCellData(satdgf_vtk);
+		if (_inifile.get<bool>("output.vertexData")) {
+			vtkwriter.addVertexData(udgf_vtk);
+			vtkwriter.addVertexData(fluxdgf_vtk);
+			vtkwriter.addVertexData(condgf_vtk);
+			vtkwriter.addVertexData(waterdgf_vtk);
+			vtkwriter.addVertexData(satdgf_vtk);
+		}
+		else {
+			vtkwriter.addCellData(udgf_vtk);
+			vtkwriter.addCellData(fluxdgf_vtk);
+			vtkwriter.addCellData(condgf_vtk);
+			vtkwriter.addCellData(waterdgf_vtk);
+			vtkwriter.addCellData(satdgf_vtk);
+		}
 	}
 
 	/// Write the VTK files for the current solution unew