Dune::IndexSet< GridImp, IndexSetImp, IndexTypeImp, TypesImp > Class Template Reference

Index Set Interface base class. More...

#include <dune/grid/common/indexidset.hh>

Classes
struct	Codim
	Export the type of the entity used as parameter in the index(...) method. More...

Public Types
typedef IndexTypeImp	IndexType
	The type used for the indices.
typedef TypesImp	Types
	iterator range for geometry types in domain

Public Member Functions
Index access from entity
template<int cc>
IndexType	index (const typename Traits::template Codim< cc >::Entity &e) const
	Map entity to index. The result of calling this method with an entity that is not in the index set is undefined. More...
template<class Entity >
IndexType	index (const Entity &e) const
	Map entity to index. Easier to use than the above because codimension template parameter need not be supplied explicitly. The result of calling this method with an entity that is not in the index set is undefined. More...
template<int cc>
IndexType	subIndex (const typename Traits::template Codim< cc >::Entity &e, int i, unsigned int codim) const
	Map a subentity to an index. More...
template<class Entity >
IndexType	subIndex (const Entity &e, int i, unsigned int codim) const
	Map a subentity to an index. More...
Access to entity set
Types	types (int codim) const
	obtain all geometry types of entities in domain More...

Static Public Attributes
static const int	dimension = remove_const< GridImp >::type::dimension
	dimension of the grid (maximum allowed codimension)

Detailed Description

template<class GridImp, class IndexSetImp, class IndexTypeImp, class TypesImp>
class Dune::IndexSet< GridImp, IndexSetImp, IndexTypeImp, TypesImp >

Index Set Interface base class.

This class template is used as a base class for all index set implementations. It uses the Barton-Nackman trick to ensure conformity to the interface.

Template Parameters

GridImp	Type that is a model of Dune::Grid.
IndexSetImp	Type that is a model of Dune::IndexSet.
IndexTypeImp	The type used by IndexSetImp to store the indices
TypesImp	iterator range for all geometry types in domain

Overview

An index set provides a map

\[ m : E \to \mathbf{N}\]

where \(E\) is a subset of the entities of a grid and \(\mathbf{N}\) is the set of natural numbers (including 0).

We define the subsets

\[ E_g^c = \{e\in E \ | \ \textrm{$e$ has codimension $c$ and geometry type $g$} \}.\]

The index map \(m\) has the following properties:

• It is unique within the subsets \(E_g^c\), i.e. for any \(e,e^\prime\in E_g^c\) we have \(e\neq e^\prime \rightarrow m(e)\neq m(e^\prime)\).
• It is consecutive and zero-starting within the subsets \(E_g^c\), i.e. we have \(0\leq m(e) < |E_g^c|\) for any \(e\in E_g^c\).

Index sets are used to assign user defined data (e.g. degrees of freedom of a discretization) to entities of the grid. For efficiency reasons the preferred data structure for user data is the array. In order to access the data from the entity, its index (with respect to an index set - there may be several) is evaluated and used as an index to an array (or some other container providing random access).

Usually an index set is not used directly but a Mapper is used to compute the array index from the information supplied by an index set.

It is important to note that the index assigned to an entity may change during grid modification (i.e. refinement or dynamic load balancing). The user is responsible for reorganizing the information stored in the external arrays appropriately. In order to do this the IdSet concept is supplied.

Level index

Index set where \(E\) corresponds to all entities of a given grid level. All grid implementations provide level indices.

Leaf Index

Index set where \(E\) corresponds to all entities of the leaf grid. All grid implementations provide a leaf index.

Member Function Documentation

index() [1/2]

template<class GridImp , class IndexSetImp , class IndexTypeImp , class TypesImp >

template<class Entity >

IndexType Dune::IndexSet< GridImp, IndexSetImp, IndexTypeImp, TypesImp >::index ( const Entity &  e ) const

inline

Map entity to index. Easier to use than the above because codimension template parameter need not be supplied explicitly. The result of calling this method with an entity that is not in the index set is undefined.

Parameters

e	Reference to codim cc entity. Since entity knows its codimension, automatic extraction is possible.

Returns

An index in the range 0 ... Max number of entities in set - 1.

References Dune::Entity< cd, dim, GridImp, EntityImp >::codimension.

index() [2/2]

template<class GridImp , class IndexSetImp , class IndexTypeImp , class TypesImp >

template<int cc>

IndexType Dune::IndexSet< GridImp, IndexSetImp, IndexTypeImp, TypesImp >::index ( const typename Traits::template Codim< cc >::Entity &  e ) const

inline

Map entity to index. The result of calling this method with an entity that is not in the index set is undefined.

Parameters

e	Reference to codim cc entity, where cc is the template parameter of the function.

Returns

An index in the range 0 ... Max number of entities in set - 1.

subIndex() [1/2]

template<class GridImp , class IndexSetImp , class IndexTypeImp , class TypesImp >

template<class Entity >

IndexType Dune::IndexSet< GridImp, IndexSetImp, IndexTypeImp, TypesImp >::subIndex ( const Entity &  e, int  i, unsigned int  codim  ) const

inline

Map a subentity to an index.

The result of calling this method with an entity that is not in the index set is undefined.

Note

This method exists for convenience only. It extracts the codimension from the type of the entity, which can be guessed by the compiler.

Template Parameters

Entity

type of entity (must be GridImp::Codim< cc >::Entity for some cc)

Parameters

[in]	e	reference to entity
[in]	i	number subentity of e within the codimension
[in]	codim	codimension of the subentity we're interested in

Returns

An index in the range 0 ... Max number of entities in set - 1.

References Dune::Entity< cd, dim, GridImp, EntityImp >::codimension.

subIndex() [2/2]

template<class GridImp , class IndexSetImp , class IndexTypeImp , class TypesImp >

template<int cc>

IndexType Dune::IndexSet< GridImp, IndexSetImp, IndexTypeImp, TypesImp >::subIndex ( const typename Traits::template Codim< cc >::Entity &  e, int  i, unsigned int  codim  ) const

inline

Map a subentity to an index.

The result of calling this method with an entity that is not in the index set is undefined.

Template Parameters

cc	codimension of the entity

Parameters

[in]	e	reference to codimension cc entity
[in]	i	number subentity of e within the codimension
[in]	codim	codimension of the subentity we're interested in (must satisfy cc <= codim <= dimension)

Returns

An index in the range 0 ... Max number of entities in set - 1.

types()

template<class GridImp , class IndexSetImp , class IndexTypeImp , class TypesImp >

Types Dune::IndexSet< GridImp, IndexSetImp, IndexTypeImp, TypesImp >::types ( int  codim ) const

inline

obtain all geometry types of entities in domain

This method returns an iterator range (something that behaves like Dune::IteratorRange) visiting all geometry types of codimension codim in the domain of the index map exactly once. The iterator must implement the concept of a forward iterator (in the sense of the STL). The elements in the iterator range are required to be of type Dune::GeometryType.

Parameters

[in]

codim

a valid codimension

Returns

iterator range over Const reference to a vector of geometry types.

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

• dune/grid/common/grid.hh
• dune/grid/common/indexidset.hh