Please I would really appreciate if someone could show me how to mark mshr.cpp.CSGDifference objects. Something like this is not implemented in FENICS:
shell = Cylinder(Point(0, 0, 0), Point(0, 0, l_shell), r_shell, r_shell) -
Cylinder(Point(0, 0, 0), Point(0, 0, l_shell), r_shell - 3, r_shell - 3)
shell.mark(materials, 1)
It gives the error:
'mshr.cpp.CSGDifference' object has no attribute 'mark'
is there a workaround? I have tried other methods but I am having issues with those.