[dune-fem] VTK output format

[Robert Kloefkorn]

> if I read the code right in dune/fem/io/file/output.hh, the difference
> between vtk-cell and vtk-vertex output format (for the VTK writer) is,
> that vtk-vertex results in a continuous reconstruction, sucht that, for
> instance, p.w. constant cell data can also be used for, e.g. plotting
> coutour lines etc. in Paraview.
>
> Is that correct?

Hi Claus,

that's correct.

> BTW: has Paraview any intrinsic method to plot kind-of countour plots
> from p.w. constant cell data?

You can convert cell data to point data. I'm not sure, whether this 
works for piecewise constant data.

Best,

Robert