Form.h¶

Note

The documentation on this page was automatically extracted from the DOLFIN C++ code and may need to be edited or expanded.

class Form¶

Parent class(es)

Hierarchical

Base class for UFC code generated by FFC for DOLFIN with option -l.

A note on the order of trial and test spaces: FEniCS numbers argument spaces starting with the leading dimension of the corresponding tensor (matrix). In other words, the test space is numbered 0 and the trial space is numbered 1. However, in order to have a notation that agrees with most existing finite element literature, in particular

a = a(u, v)

the spaces are numbered from right to

a: V_1 x V_0 -> R

Note

Figure out how to write this in math mode without it getting messed up in the Python version.

This is reflected in the ordering of the spaces that should be supplied to generated subclasses. In particular, when a bilinear form is initialized, it should be initialized as

a(V_1, V_0) = ...

where V_1 is the trial space and V_0 is the test space. However, when a form is initialized by a list of argument spaces (the variable function_spaces in the constructors below, the list of spaces should start with space number 0 (the test space) and then space number 1 (the trial space).

Form(std::size_t rank, std::size_t num_coefficients)¶

Create form of given rank with given number of coefficients

Arguments

rank (std::size_t): The rank.
num_coefficients (std::size_t): The number of coefficients.

Form(std::shared_ptr<const ufc::form> ufc_form, std::vector<std::shared_ptr<const FunctionSpace>> function_spaces)¶

Create form (shared data)

Arguments

ufc_form (ufc::form): The UFC form.
function_spaces (std::vector<FunctionSpace>): Vector of function spaces.

std::size_t rank() const¶

Return rank of form (bilinear form = 2, linear form = 1, functional = 0, etc)

Returns

std::size_t: The rank of the form.

std::size_t num_coefficients() const¶

Return number of coefficients

Returns

std::size_t: The number of coefficients.

std::size_t original_coefficient_position(std::size_t i) const¶

Return original coefficient position for each coefficient (0 <= i < n)

Returns

std::size_t: The position of coefficient i in original ufl form coefficients.

std::vector<std::size_t> coloring(std::size_t entity_dim) const¶

Return coloring type for colored (multi-threaded) assembly of form over a mesh entity of a given dimension

Arguments

entity_dim (std::size_t): Dimension.

Returns

std::vector<std::size_t>: Coloring type.

void set_mesh(std::shared_ptr<const Mesh> mesh)¶

Set mesh, necessary for functionals when there are no function spaces

Arguments

mesh (Mesh): The mesh.

std::shared_ptr<const Mesh> mesh() const¶

Extract common mesh from form

Returns

Mesh: Shared pointer to the mesh.

std::shared_ptr<const FunctionSpace> function_space(std::size_t i) const¶

Return function space for given argument

Arguments

i (std::size_t): Index

Returns

FunctionSpace: Function space shared pointer.

std::vector<std::shared_ptr<const FunctionSpace>> function_spaces() const¶

Return function spaces for arguments

Returns

std::vector<FunctionSpace>: Vector of function space shared pointers.

void set_coefficient(std::size_t i, std::shared_ptr<const GenericFunction> coefficient)¶

Set coefficient with given number (shared pointer version)

Arguments

i (std::size_t): The given number.
coefficient (GenericFunction): The coefficient.

void set_coefficient(std::string name, std::shared_ptr<const GenericFunction> coefficient)¶

Set coefficient with given name (shared pointer version)

Arguments

name (std::string): The name.
coefficient (GenericFunction): The coefficient.

void set_coefficients(std::map<std::string, std::shared_ptr<const GenericFunction>> coefficients)¶

Set all coefficients in given map. All coefficients in the given map, which may contain only a subset of the coefficients of the form, will be set.

Arguments

coefficients (std::map<std::string, GenericFunction>): The map of coefficients.

void set_some_coefficients(std::map<std::string, std::shared_ptr<const GenericFunction>> coefficients)¶

Set some coefficients in given map. Each coefficient in the given map will be set, if the name of the coefficient matches the name of a coefficient in the form.

This is useful when reusing the same coefficient map for several forms, or when some part of the form has been outcommented (for testing) in the UFL file, which means that the coefficient and attaching it to the form does not need to be outcommented in a C++ program using code from the generated UFL file.

Arguments

coefficients (std::map<std::string, GenericFunction>): The map of coefficients.

std::shared_ptr<const GenericFunction> coefficient(std::size_t i) const¶

Return coefficient with given number

Arguments

i (std::size_t): Index

Returns

GenericFunction: The coefficient.

std::shared_ptr<const GenericFunction> coefficient(std::string name) const¶

Return coefficient with given name

Arguments

name (std::string): The name.

Returns

GenericFunction: The coefficient.

std::vector<std::shared_ptr<const GenericFunction>> coefficients() const¶

Return all coefficients

Returns

std::vector<GenericFunction>: All coefficients.

std::size_t coefficient_number(const std::string &name) const¶

Return the number of the coefficient with this name

Arguments

name (std::string): The name.

Returns

std::size_t: The number of the coefficient with the given name.

std::string coefficient_name(std::size_t i) const¶

Return the name of the coefficient with this number

Arguments

i (std::size_t): The number

Returns

std::string: The name of the coefficient with the given number.

std::shared_ptr<const MeshFunction<std::size_t>> cell_domains() const¶

Return cell domains (zero pointer if no domains have been specified)

Returns

MeshFunction <std::size_t>: The cell domains.

std::shared_ptr<const MeshFunction<std::size_t>> exterior_facet_domains() const¶

Return exterior facet domains (zero pointer if no domains have been specified)

Returns

std::shared_ptr<MeshFunction <std::size_t>>: The exterior facet domains.

std::shared_ptr<const MeshFunction<std::size_t>> interior_facet_domains() const¶

Return interior facet domains (zero pointer if no domains have been specified)

Returns

MeshFunction <std::size_t>: The interior facet domains.

std::shared_ptr<const MeshFunction<std::size_t>> vertex_domains() const¶

Return vertex domains (zero pointer if no domains have been specified)

Returns

MeshFunction <std::size_t>: The vertex domains.

void set_cell_domains(std::shared_ptr<const MeshFunction<std::size_t>> cell_domains)¶

Set cell domains

Arguments

cell_domains (MeshFunction <std::size_t>): The cell domains.

void set_exterior_facet_domains(std::shared_ptr<const MeshFunction<std::size_t>> exterior_facet_domains)¶

Set exterior facet domains

Arguments

exterior_facet_domains (MeshFunction <std::size_t>): The exterior facet domains.

void set_interior_facet_domains(std::shared_ptr<const MeshFunction<std::size_t>> interior_facet_domains)¶

Set interior facet domains

Arguments

interior_facet_domains (MeshFunction <std::size_t>): The interior facet domains.

void set_vertex_domains(std::shared_ptr<const MeshFunction<std::size_t>> vertex_domains)¶

Set vertex domains

Arguments

vertex_domains (MeshFunction <std::size_t>): The vertex domains.

std::shared_ptr<const ufc::form> ufc_form() const¶

Return UFC form shared pointer

Returns

ufc::form: The UFC form.

void check() const¶: Check function spaces and coefficients

Equation operator==(const Form &rhs) const¶: Comparison operator, returning equation lhs == rhs

Equation operator==(int rhs) const¶: Comparison operator, returning equation lhs == 0