Defining subdomains for two different materials

[dokken]

This can either be done with a geometrical description, as shown in this tutorial: https://fenicsproject.org/docs/dolfin/1.4.0/python/demo/documented/subdomains-poisson/python/documentation.html

You can Also use a gmesh to define the cell function, and load it as described here:

Transitioning from mesh.xml to mesh.xdmf, from dolfin-convert to meshio

As you can see in the code snippet above, I first read the boundary data to the file mf.xdmf. this is equivalent to facet_region.xml. For the cellfunction: meshio.write("cf.xdmf", meshio.Mesh( points=msh.points, cells={"tetra": msh.cells["tetra"]}, cell_data={"tetra": {"name_to_read": msh.cell_data["tetra"]["gmsh:physical"]}})) mvc = MeshValueCollection("size_t", mesh, 3) with XDMFFile("cf.xdmf") as infile: infile.read(mvc, "name_to_read") cf = cpp.mesh.…