Is it possible to write xdmf attribute 'VisualisationVector' to master hdf5 file?

Question

I'm using a master hdf5 file for input/output and creating separate xdmf/h5 pairs for visualizing my variables. When I create the xdmf output the variable has all of the same attributes as it does in the master hdf5 file, but also has an additional 'VisualisationVector' attribute that I assume must be necessary for a reader such as ParaView to process the data. Is it possible to write the 'VisualisatonVector' attribute for each variable to my master hdf5 file so I can have a single hdf5 file with separate xdmf files for the variable visualizations? This would be as an alternative to the current setup where I have my master hdf5 and then additional hdf5 files for each specific xdmf output.

Answer 1

The VisualisationVector exists as a separate idea, because XDMF really only supports vertex or cell centred data (actually not quite true, as quadratic elements can be represented, but that is not supported in DOLFIN yet). Higher order FunctionSpaces are interpolated to vertex-centred for visualisation. Clearly that is not acceptable for data analysis, so you can save the full Vector separately.

What you are asking for could be implemented, but if anything, most demand has been for separate h5 files (to mitigate against data loss in case of a crash). HDF5 is not very tolerant of unclosed files...