Add reasonable subsampling to vtkwriters!

python/dune/perftool/pdelab/driver/vtk.py

@@ -41,7 +41,7 @@ def type_vtkwriter():
 @preamble
 def define_subsamplinglevel(name):
     ini = name_initree()
-    return "int {} = {}.get<int>(\"vtk.subsamplinglevel\", 0);".format(name, ini)
+    return "int {} = {}.get<int>(\"vtk.subsamplinglevel\", {});".format(name, ini, max(get_trial_element().degree() - 1, 0))
 
 
 def name_subsamplinglevel():