#include <Expression.h>

Inheritance diagram for dolfin::Expression:

[legend]

Collaboration diagram for dolfin::Expression:

Public Member Functions
	Expression ()
	Create scalar expression.

	Expression (std::size_t dim)

	Expression (std::size_t dim0, std::size_t dim1)

	Expression (std::vector< std::size_t > value_shape)

	Expression (const Expression &expression)

virtual	~Expression ()
	Destructor.

virtual void	eval (Array< double > &values, const Array< double > &x, const ufc::cell &cell) const override

virtual void	eval (Eigen::Ref< Eigen::VectorXd > values, Eigen::Ref< const Eigen::VectorXd > x, const ufc::cell &cell) const override

virtual void	eval (Array< double > &values, const Array< double > &x) const override

virtual void	eval (Eigen::Ref< Eigen::VectorXd > values, Eigen::Ref< const Eigen::VectorXd > x) const override

virtual std::size_t	value_rank () const override

virtual std::size_t	value_dimension (std::size_t i) const override

virtual std::vector< std::size_t >	value_shape () const override

virtual void	set_property (std::string name, double value)

virtual double	get_property (std::string name) const

virtual void	set_generic_function (std::string name, std::shared_ptr< GenericFunction > f)

virtual std::shared_ptr< dolfin::GenericFunction >	get_generic_function (std::string name) const

virtual void	restrict (double w, const FiniteElement &element, const Cell &dolfin_cell, const double coordinate_dofs, const ufc::cell &ufc_cell) const override

virtual void	compute_vertex_values (std::vector< double > &vertex_values, const Mesh &mesh) const override

virtual std::shared_ptr< const FunctionSpace >	function_space () const override

Public Member Functions inherited from dolfin::GenericFunction
	GenericFunction ()
	Constructor.

virtual	~GenericFunction ()
	Destructor.

virtual void	update () const
	Update off-process ghost coefficients.

double	operator() (double x) const
	Evaluation at given point (scalar function)

double	operator() (double x, double y) const
	Evaluation at given point (scalar function)

double	operator() (double x, double y, double z) const
	Evaluation at given point (scalar function)

double	operator() (const Point &p) const
	Evaluation at given point (scalar function)

void	operator() (Array< double > &values, double x) const
	Evaluation at given point (vector-valued function)

void	operator() (Array< double > &values, double x, double y) const
	Evaluation at given point (vector-valued function)

void	operator() (Array< double > &values, double x, double y, double z) const
	Evaluation at given point (vector-valued function)

void	operator() (Array< double > &values, const Point &p) const
	Evaluation at given point (vector-valued function)

std::size_t	value_size () const
	Evaluation at given point. More...

virtual void	evaluate (double values, const double coordinates, const ufc::cell &cell) const override

Public Member Functions inherited from dolfin::Variable
	Variable ()
	Create unnamed variable.

	Variable (const std::string name, const std::string label)
	Create variable with given name and label.

	Variable (const Variable &variable)
	Copy constructor.

virtual	~Variable ()
	Destructor.

const Variable &	operator= (const Variable &variable)
	Assignment operator.

void	rename (const std::string name, const std::string label)
	Rename variable.

std::string	name () const
	Return name.

std::string	label () const
	Return label (description)

std::size_t	id () const

virtual std::string	str (bool verbose) const
	Return informal string representation (pretty-print)

Protected Attributes
std::vector< std::size_t >	_value_shape

Additional Inherited Members
Public Attributes inherited from dolfin::Variable
Parameters	parameters
	Parameters.

Protected Member Functions inherited from dolfin::GenericFunction
void	restrict_as_ufc_function (double w, const FiniteElement &element, const Cell &dolfin_cell, const double coordinate_dofs, const ufc::cell &ufc_cell) const
	Restrict as UFC function (by calling eval)

Detailed Description

This class represents a user-defined expression. Expressions can be used as coefficients in variational forms or interpolated into finite element spaces.

An expression is defined by overloading the eval() method. Users may choose to overload either a simple version of eval(), in the case of expressions only depending on the coordinate x, or an optional version for expressions depending on x and mesh data like cell indices or facet normals.

The geometric dimension (the size of x) and the value rank and dimensions of an expression must supplied as arguments to the constructor.

Constructor & Destructor Documentation

◆ Expression() [1/4]

Expression::Expression ( std::size_t dim )

explicit

Create vector-valued expression with given dimension.

Parameters

dim	(std::size_t) Dimension of the vector-valued expression.

◆ Expression() [2/4]

Expression::Expression	(	std::size_t	dim0,
		std::size_t	dim1
	)

Create matrix-valued expression with given dimensions.

Parameters

dim0	(std::size_t) Dimension (rows).
dim1	(std::size_t) Dimension (columns).

◆ Expression() [3/4]

Expression::Expression ( std::vector< std::size_t > value_shape )

explicit

Create tensor-valued expression with given shape.

Parameters

value_shape (std::vector<std::size_t>) Shape of expression.

◆ Expression() [4/4]

Expression::Expression ( const Expression & expression )

Copy constructor

Parameters

expression (Expression) Object to be copied.

Member Function Documentation

◆ compute_vertex_values()

void Expression::compute_vertex_values	(	std::vector< double > &	vertex_values,
		const Mesh &	mesh
	)		const

overridevirtual

Compute values at all mesh vertices.

Parameters

vertex_values	(Array<double>) The values at all vertices.
mesh	(Mesh) The mesh.

Implements dolfin::GenericFunction.

Reimplemented in dolfin::MeshDisplacement.

◆ eval() [1/4]

void Expression::eval	(	Array< double > &	values,
		const Array< double > &	x,
		const ufc::cell &	cell
	)		const

overridevirtual

Evaluate at given point in given cell (deprecated)

Parameters

values	(Array<double>) The values at the point.
x	(Array<double>) The coordinates of the point.
cell	(ufc::cell) The cell which contains the given point.

Reimplemented from dolfin::GenericFunction.

Reimplemented in dolfin::MeshDisplacement, dolfin::SpecialFacetFunction, dolfin::FacetArea, and dolfin::MeshCoordinates.

◆ eval() [2/4]

void Expression::eval	(	Eigen::Ref< Eigen::VectorXd >	values,
		Eigen::Ref< const Eigen::VectorXd >	x,
		const ufc::cell &	cell
	)		const

overridevirtual

Evaluate at given point in given cell

Parameters

values	(Eigen::Ref<Eigen::VectorXd>) The values at the point.
x	(Eigen::Ref<const Eigen::VectorXd>) The coordinates of the point.
cell	(ufc::cell) The cell which contains the given point.

Reimplemented from dolfin::GenericFunction.

◆ eval() [3/4]

void Expression::eval	(	Array< double > &	values,
		const Array< double > &	x
	)		const

overridevirtual

Evaluate at given point (deprecated)

Parameters

values	(Array<double>) The values at the point.
x	(Array<double>) The coordinates of the point.

Reimplemented from dolfin::GenericFunction.

Reimplemented in dolfin::Constant.

◆ eval() [4/4]

void Expression::eval	(	Eigen::Ref< Eigen::VectorXd >	values,
		Eigen::Ref< const Eigen::VectorXd >	x
	)		const

overridevirtual

Evaluate at given point.

Parameters

values	(Eigen::Ref<Eigen::VectorXd>) The values at the point.
x	(Eigen::Ref<const Eigen::VectorXd>) The coordinates of the point.

Reimplemented from dolfin::GenericFunction.

Reimplemented in dolfin::Constant.

◆ function_space()

std::shared_ptr< const FunctionSpace > Expression::function_space ( ) const

overridevirtual

Return shared pointer to function space (NULL) Expression does not have a FunctionSpace

Returns: FunctionSpace Return the shared pointer.

Implements dolfin::GenericFunction.

◆ get_generic_function()

std::shared_ptr< GenericFunction > Expression::get_generic_function ( std::string name ) const

virtual

Property getter for type "GenericFunction" Used in pybind11 Python interface to get the value of a python attribute

◆ get_property()

double Expression::get_property ( std::string name ) const

virtual

Property getter for type "double" Used in pybind11 Python interface to get the value of a python attribute

◆ restrict()

void Expression::restrict	(	double *	w,
		const FiniteElement &	element,
		const Cell &	dolfin_cell,
		const double *	coordinate_dofs,
		const ufc::cell &	ufc_cell
	)		const

overridevirtual

Restrict function to local cell (compute expansion coefficients w).

Parameters

w	(list of doubles) Expansion coefficients.
element	(FiniteElement) The element.
dolfin_cell	(Cell) The cell.
coordinate_dofs	(double*) The coordinates
ufc_cell	(ufc::cell) The ufc::cell.

Implements dolfin::GenericFunction.

◆ set_generic_function()

void Expression::set_generic_function	(	std::string	name,
		std::shared_ptr< GenericFunction >	f
	)

virtual

Property setter for type "GenericFunction" Used in pybind11 Python interface to attach a value to a python attribute

◆ set_property()

void Expression::set_property	(	std::string	name,
		double	value
	)

virtual

Property setter for type "double" Used in pybind11 Python interface to attach a value to a python attribute

◆ value_dimension()

std::size_t Expression::value_dimension ( std::size_t i ) const

overridevirtual

Return value dimension for given axis.

Parameters

i	(std::size_t) Integer denoting the axis to use.

Returns: std::size_t The value dimension (for the given axis).

Implements dolfin::GenericFunction.

◆ value_rank()

std::size_t Expression::value_rank ( ) const

overridevirtual

Return value rank.

Returns: std::size_t The value rank.

Implements dolfin::GenericFunction.

◆ value_shape()

std::vector< std::size_t > Expression::value_shape ( ) const

overridevirtual

Return value shape

Returns: std::vector<std::size_t> The value shape.

Implements dolfin::GenericFunction.

The documentation for this class was generated from the following files:

/home/fenics/shared/dolfin/dolfin/function/Expression.h
/home/fenics/shared/dolfin/dolfin/function/Expression.cpp

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Expression() [1/4]

◆ Expression() [2/4]

◆ Expression() [3/4]

◆ Expression() [4/4]

Member Function Documentation

◆ compute_vertex_values()

◆ eval() [1/4]

◆ eval() [2/4]

◆ eval() [3/4]

◆ eval() [4/4]

◆ function_space()

◆ get_generic_function()

◆ get_property()

◆ restrict()

◆ set_generic_function()

◆ set_property()

◆ value_dimension()

◆ value_rank()

◆ value_shape()