Applying different valued matrix according to subdomain

[dokken]

Create a tensor function space of cellwise constant variables (DG 0).

Different material properties in subdomains, tensor instead of scalar

How do you expect a tensor to be assigned to a scalar function space? The space ("CG", 1) contains one degree of freedom at any point. It does not make sense to try to add a scalar to it. If you want to do so, you need to use a TensorElement or a TensorFunctionSpace as shown for a dummy rho below: import dolfinx from mpi4py import MPI import ufl import numpy as np mesh = dolfinx.mesh.create_unit_square(MPI.COMM_WORLD, 10, 10) el = ufl.TensorElement("Lagrange", mesh.ufl_cell(), 1, shape=(2, 2…