Пример #1
0
    if edgefields:
        fh.write("CELL_DATA {0}\n".format(elems.shape[0]))
        for n,f in edgefields:
            PUTFIELD(n,f)
            
    fh.close()





if __name__=="__main__":
    from dolfin import UnitSquareMesh, Function, FunctionSpace, VectorFunctionSpace, TensorFunctionSpace, Expression

    mesh = UnitSquareMesh(10,10)
    S=FunctionSpace(mesh,"DG",0)
    V=VectorFunctionSpace(mesh,"DG",0)
    T=TensorFunctionSpace(mesh,"DG",0)
    Tsym = TensorFunctionSpace(mesh,"DG",0,symmetry=True)

    s = Function(S)
    s.interpolate(Expression('x[0]',element=S.ufl_element()))
    v = Function(V)
    v.interpolate(Expression(('x[0]','x[1]'),element=V.ufl_element()))
    t = Function(T)
    t.interpolate(Expression(( ('x[0]','1.0'),('2.0','x[1]')),element=T.ufl_element()))
    ts = Function(Tsym)
    ts.interpolate(Expression(( ('x[0]','1.0'),('x[1]',)),element=Tsym.ufl_element()))
    
    write_vtk_f("test.vtk",cellfunctions={'s':s,'v':v,'t':t,'tsym':ts})
Пример #2
0
class MeshMotion(AbstractMeshMotion):
    def __init__(self, V, subdomains, shape_parametrization_expression):
        # Store dolfin data structure related to the geometrical parametrization
        self.mesh = subdomains.mesh()
        self.subdomains = subdomains
        self.reference_coordinates = self.mesh.coordinates().copy()
        self.deformation_V = VectorFunctionSpace(self.mesh, "Lagrange", 1)
        self.subdomain_id_to_deformation_dofs = dict()  # from int to list
        for cell in cells(self.mesh):
            subdomain_id = int(
                self.subdomains[cell]
            ) - 1  # tuple start from 0, while subdomains from 1
            if subdomain_id not in self.subdomain_id_to_deformation_dofs:
                self.subdomain_id_to_deformation_dofs[subdomain_id] = list()
            dofs = self.deformation_V.dofmap().cell_dofs(cell.index())
            for dof in dofs:
                global_dof = self.deformation_V.dofmap().local_to_global_index(
                    dof)
                if (self.deformation_V.dofmap().ownership_range()[0] <=
                        global_dof and global_dof <
                        self.deformation_V.dofmap().ownership_range()[1]):
                    self.subdomain_id_to_deformation_dofs[subdomain_id].append(
                        dof)
        # In parallel some subdomains may not be present on all processors. Fill in
        # the dict with empty lists if that is the case
        mpi_comm = self.mesh.mpi_comm()
        min_subdomain_id = mpi_comm.allreduce(min(
            self.subdomain_id_to_deformation_dofs.keys()),
                                              op=MIN)
        max_subdomain_id = mpi_comm.allreduce(max(
            self.subdomain_id_to_deformation_dofs.keys()),
                                              op=MAX)
        for subdomain_id in range(min_subdomain_id, max_subdomain_id + 1):
            if subdomain_id not in self.subdomain_id_to_deformation_dofs:
                self.subdomain_id_to_deformation_dofs[subdomain_id] = list()
        # Subdomain numbering is contiguous
        assert min(self.subdomain_id_to_deformation_dofs.keys()) == 0
        assert len(self.subdomain_id_to_deformation_dofs.keys()) == max(
            self.subdomain_id_to_deformation_dofs.keys()) + 1

        # Store the shape parametrization expression
        self.shape_parametrization_expression = shape_parametrization_expression
        assert len(self.shape_parametrization_expression) == len(
            self.subdomain_id_to_deformation_dofs.keys())

        # Prepare storage for displacement expression, computed by init()
        self.displacement_expression = list()

    def init(self, problem):
        if len(self.displacement_expression
               ) == 0:  # avoid initialize multiple times
            # Preprocess the shape parametrization expression to convert it in the displacement expression
            # This cannot be done during __init__ because at construction time the number
            # of parameters is still unknown

            # Declare first some sympy simbolic quantities, needed by ccode
            from rbnics.shape_parametrization.utils.symbolic import sympy_symbolic_coordinates
            x = sympy_symbolic_coordinates(self.mesh.geometry().dim(),
                                           MatrixSymbol)
            mu = MatrixSymbol("mu", len(problem.mu), 1)

            # Then carry out the proprocessing
            for shape_parametrization_expression_on_subdomain in self.shape_parametrization_expression:
                displacement_expression_on_subdomain = list()
                assert len(shape_parametrization_expression_on_subdomain
                           ) == self.mesh.geometry().dim()
                for (
                        component, shape_parametrization_component_on_subdomain
                ) in enumerate(shape_parametrization_expression_on_subdomain):
                    # convert from shape parametrization T to displacement d = T - I
                    displacement_expression_component_on_subdomain = sympify(
                        shape_parametrization_component_on_subdomain +
                        " - x[" + str(component) + "]",
                        locals={
                            "x": x,
                            "mu": mu
                        })
                    displacement_expression_on_subdomain.append(
                        ccode(displacement_expression_component_on_subdomain).
                        replace(", 0]", "]"), )
                self.displacement_expression.append(
                    ParametrizedExpression(
                        problem,
                        tuple(displacement_expression_on_subdomain),
                        mu=problem.mu,
                        element=self.deformation_V.ufl_element(),
                        domain=self.mesh))

    def move_mesh(self):
        displacement = self.compute_displacement()
        ALE.move(self.mesh, displacement)

    def reset_reference(self):
        self.mesh.coordinates()[:] = self.reference_coordinates

    # Auxiliary method to deform the domain
    def compute_displacement(self):
        displacement = Function(self.deformation_V)
        assert len(self.displacement_expression) == len(
            self.shape_parametrization_expression)
        for (subdomain, displacement_expression_on_subdomain) in enumerate(
                self.displacement_expression):
            displacement_function_on_subdomain = Function(self.deformation_V)
            LagrangeInterpolator.interpolate(
                displacement_function_on_subdomain,
                displacement_expression_on_subdomain)
            subdomain_dofs = self.subdomain_id_to_deformation_dofs[subdomain]
            displacement.vector(
            )[subdomain_dofs] = displacement_function_on_subdomain.vector(
            )[subdomain_dofs]
        return displacement