def test_save_and_checkpoint_timeseries(tempdir, encoding, cell_type):
mesh = UnitSquareMesh(MPI.comm_world, 16, 16, cell_type)
filename = os.path.join(tempdir, "u2_checkpoint.xdmf")
FE = FiniteElement("CG", mesh.ufl_cell(), 2)
V = FunctionSpace(mesh, FE)
times = [0.5, 0.2, 0.1]
u_out = [None] * len(times)
u_in = [None] * len(times)
p = 0.0
def expr_eval(x):
return x[0] * p
with XDMFFile(mesh.mpi_comm(), filename, encoding=encoding) as file:
for i, p in enumerate(times):
u_out[i] = Function(V)
u_out[i].interpolate(expr_eval)
file.write_checkpoint(u_out[i], "u_out", p)
with XDMFFile(mesh.mpi_comm(), filename) as file:
for i, p in enumerate(times):
u_in[i] = file.read_checkpoint(V, "u_out", i)
for i, p in enumerate(times):
u_in[i].vector.axpy(-1.0, u_out[i].vector)
assert u_in[i].vector.norm() < 1.0e-12
# test reading last
with XDMFFile(mesh.mpi_comm(), filename) as file:
u_in_last = file.read_checkpoint(V, "u_out", -1)
u_out[-1].vector.axpy(-1.0, u_in_last.vector)
assert u_out[-1].vector.norm() < 1.0e-12
def test_clear_sub_map_data_vector(mesh):
mesh = UnitSquareMesh(8, 8)
P1 = FiniteElement("Lagrange", mesh.ufl_cell(), 1)
W = FunctionSpace(mesh, P1 * P1)
# Check block size
assert W.dofmap.index_map.block_size == 2
W.dofmap.clear_sub_map_data()
with pytest.raises(RuntimeError):
W0 = W.sub(0)
assert (W0)
with pytest.raises(RuntimeError):
W1 = W.sub(1)
assert (W1)
#
# Next, various model parameters are defined::
# Model parameters
lmbda = 1.0e-02 # surface parameter
dt = 5.0e-06 # time step
theta = 0.5 # time stepping family, e.g. theta=1 -> backward Euler, theta=0.5 -> Crank-Nicolson
# A unit square mesh with 97 (= 96 + 1) vertices in each direction is
# created, and on this mesh a
# :py:class:`FunctionSpace<dolfinx.function.FunctionSpace>`
# ``ME`` is built using a pair of linear Lagrangian elements. ::
# Create mesh and build function space
mesh = UnitSquareMesh(MPI.COMM_WORLD, 96, 96, CellType.triangle)
P1 = FiniteElement("Lagrange", mesh.ufl_cell(), 1)
ME = FunctionSpace(mesh, P1 * P1)
# Trial and test functions of the space ``ME`` are now defined::
# Define trial and test functions
du = TrialFunction(ME)
q, v = TestFunctions(ME)
# .. index:: split functions
#
# For the test functions,
# :py:func:`TestFunctions<dolfinx.functions.function.TestFunctions>` (note
# the 's' at the end) is used to define the scalar test functions ``q``
# and ``v``. The
# :py:class:`TrialFunction<dolfinx.functions.function.TrialFunction>`
