#include <deal.II/fe/fe_poly_tensor.h>

Inheritance diagram for FE_PolyTensor< PolynomialType, dim, spacedim >:

Classes
class	InternalData

Public Member Functions
	FE_PolyTensor (const unsigned int degree, const FiniteElementData< dim > &fe_data, const std::vector< bool > &restriction_is_additive_flags, const std::vector< ComponentMask > &nonzero_components)

virtual UpdateFlags	requires_update_flags (const UpdateFlags update_flags) const

virtual double	shape_value (const unsigned int i, const Point< dim > &p) const

virtual double	shape_value_component (const unsigned int i, const Point< dim > &p, const unsigned int component) const

virtual Tensor< 1, dim >	shape_grad (const unsigned int i, const Point< dim > &p) const

virtual Tensor< 1, dim >	shape_grad_component (const unsigned int i, const Point< dim > &p, const unsigned int component) const

virtual Tensor< 2, dim >	shape_grad_grad (const unsigned int i, const Point< dim > &p) const

virtual Tensor< 2, dim >	shape_grad_grad_component (const unsigned int i, const Point< dim > &p, const unsigned int component) const

Public Member Functions inherited from FiniteElement< dim, spacedim >
	FiniteElement (const FiniteElementData< dim > &fe_data, const std::vector< bool > &restriction_is_additive_flags, const std::vector< ComponentMask > &nonzero_components)

	FiniteElement (FiniteElement< dim, spacedim > &&)=default

	FiniteElement (const FiniteElement< dim, spacedim > &)=default

virtual	~FiniteElement ()=default

std::pair< std::unique_ptr< FiniteElement< dim, spacedim > >, unsigned int >	operator^ (const unsigned int multiplicity) const

virtual std::unique_ptr< FiniteElement< dim, spacedim > >	clone () const =0

virtual std::string	get_name () const =0

const FiniteElement< dim, spacedim > &	operator[] (const unsigned int fe_index) const

virtual bool	operator== (const FiniteElement< dim, spacedim > &fe) const

bool	operator!= (const FiniteElement< dim, spacedim > &) const

virtual std::size_t	memory_consumption () const

virtual Tensor< 3, dim >	shape_3rd_derivative (const unsigned int i, const Point< dim > &p) const

virtual Tensor< 3, dim >	shape_3rd_derivative_component (const unsigned int i, const Point< dim > &p, const unsigned int component) const

virtual Tensor< 4, dim >	shape_4th_derivative (const unsigned int i, const Point< dim > &p) const

virtual Tensor< 4, dim >	shape_4th_derivative_component (const unsigned int i, const Point< dim > &p, const unsigned int component) const

virtual bool	has_support_on_face (const unsigned int shape_index, const unsigned int face_index) const

virtual const FullMatrix< double > &	get_restriction_matrix (const unsigned int child, const RefinementCase< dim > &refinement_case=RefinementCase< dim >::isotropic_refinement) const

virtual const FullMatrix< double > &	get_prolongation_matrix (const unsigned int child, const RefinementCase< dim > &refinement_case=RefinementCase< dim >::isotropic_refinement) const

bool	prolongation_is_implemented () const

bool	isotropic_prolongation_is_implemented () const

bool	restriction_is_implemented () const

bool	isotropic_restriction_is_implemented () const

bool	restriction_is_additive (const unsigned int index) const

const FullMatrix< double > &	constraints (const ::internal::SubfaceCase< dim > &subface_case=::internal::SubfaceCase< dim >::case_isotropic) const

bool	constraints_are_implemented (const ::internal::SubfaceCase< dim > &subface_case=::internal::SubfaceCase< dim >::case_isotropic) const

virtual bool	hp_constraints_are_implemented () const

virtual void	get_interpolation_matrix (const FiniteElement< dim, spacedim > &source, FullMatrix< double > &matrix) const

virtual void	get_face_interpolation_matrix (const FiniteElement< dim, spacedim > &source, FullMatrix< double > &matrix) const

virtual void	get_subface_interpolation_matrix (const FiniteElement< dim, spacedim > &source, const unsigned int subface, FullMatrix< double > &matrix) const

virtual std::vector< std::pair< unsigned int, unsigned int > >	hp_vertex_dof_identities (const FiniteElement< dim, spacedim > &fe_other) const

virtual std::vector< std::pair< unsigned int, unsigned int > >	hp_line_dof_identities (const FiniteElement< dim, spacedim > &fe_other) const

virtual std::vector< std::pair< unsigned int, unsigned int > >	hp_quad_dof_identities (const FiniteElement< dim, spacedim > &fe_other) const

virtual FiniteElementDomination::Domination	compare_for_face_domination (const FiniteElement< dim, spacedim > &fe_other) const

std::pair< unsigned int, unsigned int >	system_to_component_index (const unsigned int index) const

unsigned int	component_to_system_index (const unsigned int component, const unsigned int index) const

std::pair< unsigned int, unsigned int >	face_system_to_component_index (const unsigned int index) const

unsigned int	adjust_quad_dof_index_for_face_orientation (const unsigned int index, const bool face_orientation, const bool face_flip, const bool face_rotation) const

virtual unsigned int	face_to_cell_index (const unsigned int face_dof_index, const unsigned int face, const bool face_orientation=true, const bool face_flip=false, const bool face_rotation=false) const

unsigned int	adjust_line_dof_index_for_line_orientation (const unsigned int index, const bool line_orientation) const

const ComponentMask &	get_nonzero_components (const unsigned int i) const

unsigned int	n_nonzero_components (const unsigned int i) const

bool	is_primitive () const

bool	is_primitive (const unsigned int i) const

unsigned int	n_base_elements () const

virtual const FiniteElement< dim, spacedim > &	base_element (const unsigned int index) const

unsigned int	element_multiplicity (const unsigned int index) const

const FiniteElement< dim, spacedim > &	get_sub_fe (const ComponentMask &mask) const

virtual const FiniteElement< dim, spacedim > &	get_sub_fe (const unsigned int first_component, const unsigned int n_selected_components) const

std::pair< std::pair< unsigned int, unsigned int >, unsigned int >	system_to_base_index (const unsigned int index) const

std::pair< std::pair< unsigned int, unsigned int >, unsigned int >	face_system_to_base_index (const unsigned int index) const

types::global_dof_index	first_block_of_base (const unsigned int b) const

std::pair< unsigned int, unsigned int >	component_to_base_index (const unsigned int component) const

std::pair< unsigned int, unsigned int >	block_to_base_index (const unsigned int block) const

std::pair< unsigned int, types::global_dof_index >	system_to_block_index (const unsigned int component) const

unsigned int	component_to_block_index (const unsigned int component) const

ComponentMask	component_mask (const FEValuesExtractors::Scalar &scalar) const

ComponentMask	component_mask (const FEValuesExtractors::Vector &vector) const

ComponentMask	component_mask (const FEValuesExtractors::SymmetricTensor< 2 > &sym_tensor) const

ComponentMask	component_mask (const BlockMask &block_mask) const

BlockMask	block_mask (const FEValuesExtractors::Scalar &scalar) const

BlockMask	block_mask (const FEValuesExtractors::Vector &vector) const

BlockMask	block_mask (const FEValuesExtractors::SymmetricTensor< 2 > &sym_tensor) const

BlockMask	block_mask (const ComponentMask &component_mask) const

virtual std::pair< Table< 2, bool >, std::vector< unsigned int > >	get_constant_modes () const

const std::vector< Point< dim > > &	get_unit_support_points () const

bool	has_support_points () const

virtual Point< dim >	unit_support_point (const unsigned int index) const

const std::vector< Point< dim-1 > > &	get_unit_face_support_points () const

bool	has_face_support_points () const

virtual Point< dim-1 >	unit_face_support_point (const unsigned int index) const

const std::vector< Point< dim > > &	get_generalized_support_points () const

bool	has_generalized_support_points () const

const std::vector< Point< dim-1 > > &	get_generalized_face_support_points () const

bool	has_generalized_face_support_points () const

GeometryPrimitive	get_associated_geometry_primitive (const unsigned int cell_dof_index) const

virtual void	convert_generalized_support_point_values_to_dof_values (const std::vector< Vector< double > > &support_point_values, std::vector< double > &nodal_values) const

Public Member Functions inherited from Subscriptor
	Subscriptor ()

	Subscriptor (const Subscriptor &)

	Subscriptor (Subscriptor &&) noexcept

virtual	~Subscriptor ()

Subscriptor &	operator= (const Subscriptor &)

Subscriptor &	operator= (Subscriptor &&) noexcept

void	subscribe (const char *identifier=nullptr) const

void	unsubscribe (const char *identifier=nullptr) const

unsigned int	n_subscriptions () const

void	list_subscribers () const

template<class Archive >
void	serialize (Archive &ar, const unsigned int version)

Public Member Functions inherited from FiniteElementData< dim >
	FiniteElementData (const std::vector< unsigned int > &dofs_per_object, const unsigned int n_components, const unsigned int degree, const Conformity conformity=unknown, const BlockIndices &block_indices=BlockIndices())

unsigned int	n_dofs_per_vertex () const

unsigned int	n_dofs_per_line () const

unsigned int	n_dofs_per_quad () const

unsigned int	n_dofs_per_hex () const

unsigned int	n_dofs_per_face () const

unsigned int	n_dofs_per_cell () const

template<int structdim>
unsigned int	n_dofs_per_object () const

unsigned int	n_components () const

unsigned int	n_blocks () const

const BlockIndices &	block_indices () const

unsigned int	tensor_degree () const

bool	conforms (const Conformity) const

bool	operator== (const FiniteElementData &) const

Protected Member Functions
virtual std::unique_ptr< typename FiniteElement< dim, spacedim >::InternalDataBase >	get_data (const UpdateFlags update_flags, const Mapping< dim, spacedim > &, const Quadrature< dim > &quadrature, ::internal::FEValuesImplementation::FiniteElementRelatedData< dim, spacedim > &) const

Protected Member Functions inherited from FiniteElement< dim, spacedim >
void	reinit_restriction_and_prolongation_matrices (const bool isotropic_restriction_only=false, const bool isotropic_prolongation_only=false)

TableIndices< 2 >	interface_constraints_size () const

virtual std::unique_ptr< InternalDataBase >	get_face_data (const UpdateFlags update_flags, const Mapping< dim, spacedim > &mapping, const Quadrature< dim-1 > &quadrature, ::internal::FEValuesImplementation::FiniteElementRelatedData< dim, spacedim > &output_data) const

virtual std::unique_ptr< InternalDataBase >	get_subface_data (const UpdateFlags update_flags, const Mapping< dim, spacedim > &mapping, const Quadrature< dim-1 > &quadrature, ::internal::FEValuesImplementation::FiniteElementRelatedData< dim, spacedim > &output_data) const

virtual void	fill_fe_values (const typename Triangulation< dim, spacedim >::cell_iterator &cell, const CellSimilarity::Similarity cell_similarity, const Quadrature< dim > &quadrature, const Mapping< dim, spacedim > &mapping, const typename Mapping< dim, spacedim >::InternalDataBase &mapping_internal, const ::internal::FEValuesImplementation::MappingRelatedData< dim, spacedim > &mapping_data, const InternalDataBase &fe_internal, ::internal::FEValuesImplementation::FiniteElementRelatedData< dim, spacedim > &output_data) const =0

virtual void	fill_fe_face_values (const typename Triangulation< dim, spacedim >::cell_iterator &cell, const unsigned int face_no, const Quadrature< dim-1 > &quadrature, const Mapping< dim, spacedim > &mapping, const typename Mapping< dim, spacedim >::InternalDataBase &mapping_internal, const ::internal::FEValuesImplementation::MappingRelatedData< dim, spacedim > &mapping_data, const InternalDataBase &fe_internal, ::internal::FEValuesImplementation::FiniteElementRelatedData< dim, spacedim > &output_data) const =0

virtual void	fill_fe_subface_values (const typename Triangulation< dim, spacedim >::cell_iterator &cell, const unsigned int face_no, const unsigned int sub_no, const Quadrature< dim-1 > &quadrature, const Mapping< dim, spacedim > &mapping, const typename Mapping< dim, spacedim >::InternalDataBase &mapping_internal, const ::internal::FEValuesImplementation::MappingRelatedData< dim, spacedim > &mapping_data, const InternalDataBase &fe_internal, ::internal::FEValuesImplementation::FiniteElementRelatedData< dim, spacedim > &output_data) const =0

Protected Attributes
MappingType	mapping_type

PolynomialType	poly_space

FullMatrix< double >	inverse_node_matrix

Threads::Mutex	cache_mutex

Point< dim >	cached_point

std::vector< Tensor< 1, dim > >	cached_values

std::vector< Tensor< 2, dim > >	cached_grads

std::vector< Tensor< 3, dim > >	cached_grad_grads

Protected Attributes inherited from FiniteElement< dim, spacedim >
std::vector< std::vector< FullMatrix< double > > >	restriction

std::vector< std::vector< FullMatrix< double > > >	prolongation

FullMatrix< double >	interface_constraints

std::vector< Point< dim > >	unit_support_points

std::vector< Point< dim-1 > >	unit_face_support_points

std::vector< Point< dim > >	generalized_support_points

std::vector< Point< dim-1 > >	generalized_face_support_points

Table< 2, int >	adjust_quad_dof_index_for_face_orientation_table

std::vector< int >	adjust_line_dof_index_for_line_orientation_table

std::vector< std::pair< unsigned int, unsigned int > >	system_to_component_table

std::vector< std::pair< unsigned int, unsigned int > >	face_system_to_component_table

std::vector< std::pair< std::pair< unsigned int, unsigned int >, unsigned int > >	system_to_base_table

std::vector< std::pair< std::pair< unsigned int, unsigned int >, unsigned int > >	face_system_to_base_table

BlockIndices	base_to_block_indices

std::vector< std::pair< std::pair< unsigned int, unsigned int >, unsigned int > >	component_to_base_table

const std::vector< bool >	restriction_is_additive_flags

const std::vector< ComponentMask >	nonzero_components

const std::vector< unsigned int >	n_nonzero_components_table

const bool	cached_primitivity

Additional Inherited Members
Public Types inherited from FiniteElementData< dim >
enum	Conformity { unknown = 0x00, L2 = 0x01, Hcurl = 0x02, Hdiv = 0x04, H1 = Hcurl \| Hdiv, H2 = 0x0e }

Static Public Member Functions inherited from FiniteElement< dim, spacedim >
static ::ExceptionBase &	ExcShapeFunctionNotPrimitive (int arg1)

static ::ExceptionBase &	ExcFENotPrimitive ()

static ::ExceptionBase &	ExcUnitShapeValuesDoNotExist ()

static ::ExceptionBase &	ExcFEHasNoSupportPoints ()

static ::ExceptionBase &	ExcEmbeddingVoid ()

static ::ExceptionBase &	ExcProjectionVoid ()

static ::ExceptionBase &	ExcWrongInterfaceMatrixSize (int arg1, int arg2)

static ::ExceptionBase &	ExcInterpolationNotImplemented ()

Static Public Member Functions inherited from Subscriptor
static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)

static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Public Attributes inherited from FiniteElementData< dim >
const unsigned int	dofs_per_vertex

const unsigned int	dofs_per_line

const unsigned int	dofs_per_quad

const unsigned int	dofs_per_hex

const unsigned int	first_line_index

const unsigned int	first_quad_index

const unsigned int	first_hex_index

const unsigned int	first_face_line_index

const unsigned int	first_face_quad_index

const unsigned int	dofs_per_face

const unsigned int	dofs_per_cell

const unsigned int	components

const unsigned int	degree

const Conformity	conforming_space

const BlockIndices	block_indices_data

Static Public Attributes inherited from FiniteElement< dim, spacedim >
static const unsigned int	space_dimension = spacedim

Static Public Attributes inherited from FiniteElementData< dim >
static const unsigned int	dimension = dim

Static Protected Member Functions inherited from FiniteElement< dim, spacedim >
static std::vector< unsigned int >	compute_n_nonzero_components (const std::vector< ComponentMask > &nonzero_components)

Detailed Description

template<class PolynomialType, int dim, int spacedim = dim>
class FE_PolyTensor< PolynomialType, dim, spacedim >

This class gives a unified framework for the implementation of FiniteElement classes based on Tensor valued polynomial spaces like PolynomialsBDM and PolynomialsRaviartThomas.

In essence, what this class requires is that a derived class describes to it a (vector-valued) polynomial space in which every polynomial has exactly dim vector components. The polynomial space is described through the PolynomialType template argument, which needs to provide a function of the following signature:

void compute (const Point<dim>            &unit_point,
              std::vector<Tensor<1,dim> > &values,
              std::vector<Tensor<2,dim> > &grads,
              std::vector<Tensor<3,dim> > &grad_grads) const;

For more information on the template parameter spacedim, see the documentation for the class Triangulation.

Deriving classes

This class is not a fully implemented FiniteElement class, but implements some common features of vector valued elements based on vector valued polynomial classes. What's missing here in particular is information on the topological location of the node values, and derived classes need to provide this information.

Similarly, in many cases, node functionals depend on the shape of the mesh cell, since they evaluate normal or tangential components on the faces. In order to allow for a set of transformations, the variable mapping_type has been introduced. It should needs be set in the constructor of a derived class.

Any derived class must decide on the polynomial space to use. This polynomial space should be implemented simply as a set of vector valued polynomials like PolynomialsBDM and PolynomialsRaviartThomas. In order to facilitate this implementation, which basis the polynomial space chooses is not of importance to the current class – as described next, this class handles the transformation from the basis chosen by the polynomial space template argument to the basis we want to use for finite element computations internally.

Determining the correct basis

In most cases, the basis used by the class that describes the polynomial space, \(\{\tilde\varphi_j(\hat{\mathbf x})\}\), does not match the one we want to use for the finite element description, \(\{\varphi_j(\hat{\mathbf x})\}\). Rather, we need to express the finite element shape functions as a linear combination of the basis provided by the polynomial space:

\begin{align*} \varphi_j = \sum_k c_{jk} \tilde\varphi_j. \end{align*}

These expansion coefficients \(c_{jk}\) are typically computed in the constructors of derived classes. To facilitate this, this class at first (unless told otherwise, see below), assumes that the shape functions should be exactly the ones provided by the polynomial space. In the constructor of the derived class, one then typically has code of the form

// Now compute the inverse node matrix, generating the correct
// basis functions from the raw ones. For a discussion of what
// exactly happens here, see FETools::compute_node_matrix.
const FullMatrix<double> M = FETools::compute_node_matrix(*this);
this->inverse_node_matrix.reinit(n_dofs, n_dofs);
this->inverse_node_matrix.invert(M);
// From now on, the shape functions provided by FiniteElement::shape_value
// and similar functions will be the correct ones, not
// the raw shape functions from the polynomial space anymore.

The FETools::compute_node_matrix() function explains in more detail what exactly it computes, and how; in any case, the result is that inverse_node_matrix now contains the expansion coefficients \(c_{jk}\), and the fact that this block of code now sets the matrix to a non-zero size indicates to the functions of the current class that it should from then on use the expanded basis, \(\{\varphi_j(\hat{\mathbf x})\}\), and no longer the original, "raw" basis \(\{\tilde\varphi_j(\hat{\mathbf x})\}\) when asked for values or derivatives of shape functions.

In order for this scheme to work, it is important to ensure that the size of the inverse_node_matrix be zero at the time when FETools::compute_node_matrix() is called; thus, the call to this function cannot be inlined into the last line – the result of the call really does need to be stored in the temporary object M.

Setting the transformation

In most cases, vector valued basis functions must be transformed when mapped from the reference cell to the actual grid cell. These transformations can be selected from the set MappingType and stored in mapping_type. Therefore, each constructor should contain a line like:

this->mapping_type = mapping_none;

(in case no mapping is required) or using whatever value among the ones defined in MappingType is appropriate for the element you are implementing.

See also: PolynomialsBDM, PolynomialsRaviartThomas

Author: Guido Kanschat

Date: 2005

Definition at line 140 of file fe_poly_tensor.h.

Constructor & Destructor Documentation

◆ FE_PolyTensor()

template<class PolynomialType , int dim, int spacedim>

FE_PolyTensor< PolynomialType, dim, spacedim >::FE_PolyTensor	(	const unsigned int	degree,
		const FiniteElementData< dim > &	fe_data,
		const std::vector< bool > &	restriction_is_additive_flags,
		const std::vector< ComponentMask > &	nonzero_components
	)

Constructor.

degree: constructor argument for poly. May be different from fe_data.degree.

Definition at line 145 of file fe_poly_tensor.cc.

Member Function Documentation

◆ requires_update_flags()

template<class PolynomialType , int dim, int spacedim>

UpdateFlags FE_PolyTensor< PolynomialType, dim, spacedim >::requires_update_flags ( const UpdateFlags update_flags ) const

virtual

Given a set of update flags, compute which other quantities also need to be computed in order to satisfy the request by the given flags. Then return the combination of the original set of flags and those just computed.

As an example, if update_flags contains update_gradients a finite element class will typically require the computation of the inverse of the Jacobian matrix in order to rotate the gradient of shape functions on the reference cell to the real cell. It would then return not just update_gradients, but also update_covariant_transformation, the flag that makes the mapping class produce the inverse of the Jacobian matrix.

An extensive discussion of the interaction between this function and FEValues can be found in the How Mapping, FiniteElement, and FEValues work together documentation module.

See also: UpdateFlags

Implements FiniteElement< dim, spacedim >.

Definition at line 1735 of file fe_poly_tensor.cc.

◆ shape_value()

template<class PolynomialType , int dim, int spacedim>

double FE_PolyTensor< PolynomialType, dim, spacedim >::shape_value	(	const unsigned int	i,
		const Point< dim > &	p
	)		const

virtual

Compute the (scalar) value of shape function i at the given quadrature point p. Since the elements represented by this class are vector valued, there is no such scalar value and the function therefore throws an exception.

Reimplemented from FiniteElement< dim, spacedim >.

Definition at line 173 of file fe_poly_tensor.cc.

◆ shape_value_component()

template<class PolynomialType , int dim, int spacedim>

double FE_PolyTensor< PolynomialType, dim, spacedim >::shape_value_component	(	const unsigned int	i,
		const Point< dim > &	p,
		const unsigned int	component
	)		const

virtual

Just like for shape_value(), but this function will be called when the shape function has more than one non-zero vector component. In that case, this function should return the value of the component-th vector component of the ith shape function at point p.

Reimplemented from FiniteElement< dim, spacedim >.

Definition at line 185 of file fe_poly_tensor.cc.

◆ shape_grad()

template<class PolynomialType , int dim, int spacedim>

Tensor< 1, dim > FE_PolyTensor< PolynomialType, dim, spacedim >::shape_grad	(	const unsigned int	i,
		const Point< dim > &	p
	)		const

virtual

Compute the gradient of (scalar) shape function i at the given quadrature point p. Since the elements represented by this class are vector valued, there is no such scalar value and the function therefore throws an exception.

Reimplemented from FiniteElement< dim, spacedim >.

Definition at line 217 of file fe_poly_tensor.cc.

◆ shape_grad_component()

template<class PolynomialType , int dim, int spacedim>

Tensor< 1, dim > FE_PolyTensor< PolynomialType, dim, spacedim >::shape_grad_component	(	const unsigned int	i,
		const Point< dim > &	p,
		const unsigned int	component
	)		const

virtual

Just like for shape_grad(), but this function will be called when the shape function has more than one non-zero vector component. In that case, this function should return the gradient of the component-th vector component of the ith shape function at point p.

Reimplemented from FiniteElement< dim, spacedim >.

Definition at line 229 of file fe_poly_tensor.cc.

◆ shape_grad_grad()

template<class PolynomialType , int dim, int spacedim>

Tensor< 2, dim > FE_PolyTensor< PolynomialType, dim, spacedim >::shape_grad_grad	(	const unsigned int	i,
		const Point< dim > &	p
	)		const

virtual

Compute the Hessian of (scalar) shape function i at the given quadrature point p. Since the elements represented by this class are vector valued, there is no such scalar value and the function therefore throws an exception.

Reimplemented from FiniteElement< dim, spacedim >.

Definition at line 263 of file fe_poly_tensor.cc.

◆ shape_grad_grad_component()

template<class PolynomialType , int dim, int spacedim>

Tensor< 2, dim > FE_PolyTensor< PolynomialType, dim, spacedim >::shape_grad_grad_component	(	const unsigned int	i,
		const Point< dim > &	p,
		const unsigned int	component
	)		const

virtual

Just like for shape_grad_grad(), but this function will be called when the shape function has more than one non-zero vector component. In that case, this function should return the gradient of the component-th vector component of the ith shape function at point p.

Reimplemented from FiniteElement< dim, spacedim >.

Definition at line 275 of file fe_poly_tensor.cc.

◆ get_data()

template<class PolynomialType, int dim, int spacedim = dim>

virtual std::unique_ptr<typename FiniteElement<dim,spacedim>::InternalDataBase> FE_PolyTensor< PolynomialType, dim, spacedim >::get_data	(	const UpdateFlags	update_flags,
		const Mapping< dim, spacedim > &	mapping,
		const Quadrature< dim > &	quadrature,
		::internal::FEValuesImplementation::FiniteElementRelatedData< dim, spacedim > &	output_data
	)		const

inlineprotectedvirtual

Create an internal data object and return a pointer to it of which the caller of this function then assumes ownership. This object will then be passed to the FiniteElement::fill_fe_values() every time the finite element shape functions and their derivatives are evaluated on a concrete cell. The object created here is therefore used by derived classes as a place for scratch objects that are used in evaluating shape functions, as well as to store information that can be pre-computed once and re-used on every cell (e.g., for evaluating the values and gradients of shape functions on the reference cell, for later re-use when transforming these values to a concrete cell).

This function is the first one called in the process of initializing a FEValues object for a given mapping and finite element object. The returned object will later be passed to FiniteElement::fill_fe_values() for a concrete cell, which will itself place its output into an object of type internal::FEValuesImplementation::FiniteElementRelatedData. Since there may be data that can already be computed in its final form on the reference cell, this function also receives a reference to the internal::FEValuesImplementation::FiniteElementRelatedData object as its last argument. This output argument is guaranteed to always be the same one when used with the InternalDataBase object returned by this function. In other words, the subdivision of scratch data and final data in the returned object and the output_data object is as follows: If data can be pre- computed on the reference cell in the exact form in which it will later be needed on a concrete cell, then this function should already emplace it in the output_data object. An example are the values of shape functions at quadrature points for the usual Lagrange elements which on a concrete cell are identical to the ones on the reference cell. On the other hand, if some data can be pre-computed to make computations on a concrete cell cheaper, then it should be put into the returned object for later re-use in a derive class's implementation of FiniteElement::fill_fe_values(). An example are the gradients of shape functions on the reference cell for Lagrange elements: to compute the gradients of the shape functions on a concrete cell, one has to multiply the gradients on the reference cell by the inverse of the Jacobian of the mapping; consequently, we cannot already compute the gradients on a concrete cell at the time the current function is called, but we can at least pre-compute the gradients on the reference cell, and store it in the object returned.

An extensive discussion of the interaction between this function and FEValues can be found in the How Mapping, FiniteElement, and FEValues work together documentation module. See also the documentation of the InternalDataBase class.

Parameters

[in]	update_flags	A set of UpdateFlags values that describe what kind of information the FEValues object requests the finite element to compute. This set of flags may also include information that the finite element can not compute, e.g., flags that pertain to data produced by the mapping. An implementation of this function needs to set up all data fields in the returned object that are necessary to produce the finite- element related data specified by these flags, and may already pre- compute part of this information as discussed above. Elements may want to store these update flags (or a subset of these flags) in InternalDataBase::update_each so they know at the time when FiniteElement::fill_fe_values() is called what they are supposed to compute
[in]	mapping	A reference to the mapping used for computing values and derivatives of shape functions.
[in]	quadrature	A reference to the object that describes where the shape functions should be evaluated.
[out]	output_data	A reference to the object that FEValues will use in conjunction with the object returned here and where an implementation of FiniteElement::fill_fe_values() will place the requested information. This allows the current function to already pre-compute pieces of information that can be computed on the reference cell, as discussed above. FEValues guarantees that this output object and the object returned by the current function will always be used together.

Returns: A pointer to an object of a type derived from InternalDataBase and that derived classes can use to store scratch data that can be pre- computed, or for scratch arrays that then only need to be allocated once. The calling site assumes ownership of this object and will delete it when it is no longer necessary.

Implements FiniteElement< dim, spacedim >.

Definition at line 213 of file fe_poly_tensor.h.

Member Data Documentation

◆ mapping_type

template<class PolynomialType, int dim, int spacedim = dim>

MappingType FE_PolyTensor< PolynomialType, dim, spacedim >::mapping_type

protected

The mapping type to be used to map shape functions from the reference cell to the mesh cell.

Definition at line 206 of file fe_poly_tensor.h.

◆ poly_space

template<class PolynomialType, int dim, int spacedim = dim>

PolynomialType FE_PolyTensor< PolynomialType, dim, spacedim >::poly_space

protected

The polynomial space. Its type is given by the template parameter PolynomialType.

Definition at line 420 of file fe_poly_tensor.h.

◆ inverse_node_matrix

template<class PolynomialType, int dim, int spacedim = dim>

FullMatrix<double> FE_PolyTensor< PolynomialType, dim, spacedim >::inverse_node_matrix

protected

The inverse of the matrix a_ij of node values N_i applied to polynomial p_j. This matrix is used to convert polynomials in the "raw" basis provided in poly_space to the basis dual to the node functionals on the reference cell.

This object is not filled by FE_PolyTensor, but is a chance for a derived class to allow for reorganization of the basis functions. If it is left empty, the basis in poly_space is used.

Definition at line 433 of file fe_poly_tensor.h.

◆ cache_mutex

template<class PolynomialType, int dim, int spacedim = dim>

Threads::Mutex FE_PolyTensor< PolynomialType, dim, spacedim >::cache_mutex

mutableprotected

A mutex to be used to guard access to the variables below.

Definition at line 438 of file fe_poly_tensor.h.

◆ cached_point

template<class PolynomialType, int dim, int spacedim = dim>

Point<dim> FE_PolyTensor< PolynomialType, dim, spacedim >::cached_point

mutableprotected

If a shape function is computed at a single point, we must compute all of them to apply inverse_node_matrix. In order to avoid too much overhead, we cache the point and the function values for the next evaluation.

Definition at line 445 of file fe_poly_tensor.h.

◆ cached_values

template<class PolynomialType, int dim, int spacedim = dim>

std::vector<Tensor<1,dim> > FE_PolyTensor< PolynomialType, dim, spacedim >::cached_values

mutableprotected

Cached shape function values after call to shape_value_component().

Definition at line 450 of file fe_poly_tensor.h.

◆ cached_grads

template<class PolynomialType, int dim, int spacedim = dim>

std::vector<Tensor<2,dim> > FE_PolyTensor< PolynomialType, dim, spacedim >::cached_grads

mutableprotected

Cached shape function gradients after call to shape_grad_component().

Definition at line 455 of file fe_poly_tensor.h.

◆ cached_grad_grads

template<class PolynomialType, int dim, int spacedim = dim>

std::vector<Tensor<3,dim> > FE_PolyTensor< PolynomialType, dim, spacedim >::cached_grad_grads

mutableprotected

Cached second derivatives of shape functions after call to shape_grad_grad_component().

Definition at line 461 of file fe_poly_tensor.h.

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

deal.II/fe/fe_poly_tensor.h
source/fe/fe_poly_tensor.cc

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

template<class PolynomialType, int dim, int spacedim = dim> class FE_PolyTensor< PolynomialType, dim, spacedim >

Deriving classes

Determining the correct basis

Setting the transformation

Constructor & Destructor Documentation

◆ FE_PolyTensor()

Member Function Documentation

◆ requires_update_flags()

◆ shape_value()

◆ shape_value_component()

◆ shape_grad()

◆ shape_grad_component()

◆ shape_grad_grad()

◆ shape_grad_grad_component()

◆ get_data()

Member Data Documentation

◆ mapping_type

◆ poly_space

◆ inverse_node_matrix

◆ cache_mutex

◆ cached_point

◆ cached_values

◆ cached_grads

◆ cached_grad_grads

template<class PolynomialType, int dim, int spacedim = dim>
class FE_PolyTensor< PolynomialType, dim, spacedim >