def test_save_2d_mixed(tempdir):
mesh = UnitCubeMesh(MPI.COMM_WORLD, 3, 3, 3)
P2 = ufl.VectorElement("Lagrange", mesh.ufl_cell(), 2)
P1 = ufl.FiniteElement("Lagrange", mesh.ufl_cell(), 1)
TH = P2 * P1
W = FunctionSpace(mesh, TH)
def vec_func(x):
vals = np.zeros((3, x.shape[1]))
vals[0] = x[0]
vals[1] = 0.2 * x[1]
return vals
def scal_func(x):
return 0.5 * x[0]
U = Function(W)
U.sub(0).interpolate(vec_func)
U.sub(1).interpolate(scal_func)
U.vector.ghostUpdate(addv=PETSc.InsertMode.INSERT, mode=PETSc.ScatterMode.FORWARD)
filename = os.path.join(tempdir, "u.pvd")
with VTKFile(mesh.mpi_comm(), filename, "w") as vtk:
vtk.write_function([U.sub(i) for i in range(W.num_sub_spaces())], 0.)
def test_taylor_hood_cube():
pytest.xfail("Problem with Mixed Function Spaces")
meshc = UnitCubeMesh(MPI.comm_world, 2, 2, 2)
meshf = UnitCubeMesh(MPI.comm_world, 3, 4, 5)
Ve = VectorElement("CG", meshc.ufl_cell(), 2)
Qe = FiniteElement("CG", meshc.ufl_cell(), 1)
Ze = MixedElement([Ve, Qe])
Zc = FunctionSpace(meshc, Ze)
Zf = FunctionSpace(meshf, Ze)
def z(x):
return np.row_stack((x[0] * x[1],
x[1] * x[2],
x[2] * x[0],
x[0] + 3.0 * x[1] + x[2]))
zc, zf = Function(Zc), Function(Zf)
zc.interpolate(z)
zf.interpolate(z)
mat = PETScDMCollection.create_transfer_matrix(Zc, Zf)
Zuc = Function(Zf)
mat.mult(zc.vector, Zuc.vector)
Zuc.vector.update_ghost_values()
diff = Function(Zf)
diff.assign(Zuc - zf)
assert diff.vector.norm("l2") < 1.0e-12
def test_mixed_element_interpolation():
def f(x):
return np.ones(2, x.shape[1])
mesh = UnitCubeMesh(MPI.COMM_WORLD, 3, 3, 3)
el = ufl.FiniteElement("CG", mesh.ufl_cell(), 1)
V = dolfinx.FunctionSpace(mesh, ufl.MixedElement([el, el]))
u = dolfinx.Function(V)
with pytest.raises(RuntimeError):
u.interpolate(f)
