Vorticity shows artifacts at process boundaries
As discussed earlier
Vorticity has artifacts at process boundaries. @acbauer suggested that the Xdmf reader was not providing proper ghost information. I'd rather think that it is the Vorticity filter itself messing up, as demonstrated with the enclosed Python script which uses a Wavelet (independent of Xdmf) and still showing inter-process artifacts which moves around the slice as I change the number of pvserver tasks.