dolphin subdomain plotting

[Jed Brown]

When running demo_stokes-taylor-hood.py with current matplotlib:

*** Warning: Matplotlib plotting backend does not support mesh function of dim 1. Continuing without plotting...

This is due to plot(sub_domains) with dolfin_fine_subdomains.xml.gz. Seem to me this call should either be removed from the example or (better because it's quite important for users to understand when adapting to a real problem) the plotting code should be fixed for this case.

[Jed Brown]

Related: the old version of this documentation is nicer than the new version.

[Stefano Ottolenghi]

This looks fixed as of now. I am still not sure what is the expected behavior of calling plot on a MeshFunction (at least to a single-valued one), so maybe this also needs addressing. Or maybe there’s just something I don’t know.