Get boundary points from custom cell tags

[cweickhmann]

Just a remark, as I ran into the same problem:
hherlyng has pointed out that the shape of values has to be different “now”. See his post:

Meshtags_from_entities(), incompatible function arguments

Hi mnotazio, The problem is in the shape of the values array in create_meshtags(). Changing line 72 to values = np.zeros(len(cells), dtype=np.int32) should do the trick, at least the plots generated by your code looks good when I run the code with this change. The reason this change is needed is that dolfinx.mesh.meshtags_from_entities() takes the meshtag values as an ndarray, and your syntax values = np.zeros([len(cells), 1], dtype=np.int32) creates and ndarray of ndarrays. I would recomme…