[Dune] Vector Data to VTK format?

[Christian Engwer]

Dear Arne,

> I am wondering if there is a possibility to export Vector data to  
> VTK-format in DUNE. I want to visualize the velocity field in  
> Paraview. Currently I take the norm of the velocity vector and saves  
> this to VTK-format, but I am not satisfied with this.

It depends a little bit on how you store your data. The VTKWriter can
write vertor valued data, but not necessarily all types of storage
containers. The VTKWriter stores either a simple container, which is
assumed to be scalar, or a VTKFunction, which can handle both scalar
and vector valued data. In all higherlevel modules suitable
VTKFunction exist to export the data, if you are using a different
container you have to write your own VTKFunction. THe interface is
very simple, have a look at 
http://www.dune-project.org/doc/doxygen/dune-grid-html/classDune_1_1VTKWriter_1_1VTKFunction.html

Hope that helps
  Christian