Applying Multipoint Constraint on subspace using dolfinx_mpc

[dokken]

Could you supply your full code, with 3x` encapsulation, as currently the indentation is wrong, and the code ends at finalizing the MPC, not at the end of solve.
To me, it also seems like you are importing things that are not needed, such as

@M_Jalili

from ufl.classes import *

@M_Jalili

from ufl.algorithms import *

@M_Jalili

import os

The following is unused:

@M_Jalili

def refine_cells(x, tol=1e-16):

return x[1] >= refine_length_bar + tol

and I would be careful with:

@M_Jalili

w = dolfinx.fem.Function(ME)

w_old = dolfinx.fem.Function(ME)

as those should be from your MPC space, as discussed in:

Dolfinx_mpc parallel setup

The issue is that u is not in the enhanced function space used for MPC. By re-ordering your code, and creating u from mpc.function_space, your code works: from mpi4py import MPI import numpy as np from dolfinx import fem, mesh, io, default_scalar_type import dolfinx_mpc import ufl comm = MPI.COMM_WORLD # --- Mesh and function space --- domain = mesh.create_unit_cube(comm, 20, 20, 20, ghost_mode=mesh.GhostMode.shared_facet ) domain.topology.create_connectivity(domain.topology.dim, domain.top…