Topology Class Reference

Topology stores the topology of a mesh, consisting of mesh entities and connectivity (incidence relations for the mesh entities). More...

#include <Topology.h>

Public Member Functions
	Topology (MPI_Comm comm, CellType cell_type)
	Empty Topology constructor.
	Topology (MPI_Comm comm, const std::vector< CellType > &cell_type)
	Create empty mesh topology with multiple cell types.
	Topology (const Topology &topology)=default
	Copy constructor.
	Topology (Topology &&topology)=default
	Move constructor.
	~Topology ()=default
	Destructor.
Topology &	operator= (const Topology &topology)=delete
	Assignment.
Topology &	operator= (Topology &&topology)=default
	Assignment.
int	dim () const noexcept
	Return the topological dimension of the mesh.
void	set_index_map (int dim, std::shared_ptr< const common::IndexMap > map)
	Set the IndexMap for dimension dim.
void	set_index_map (std::int8_t dim, std::int8_t i, std::shared_ptr< const common::IndexMap > map)
	Set the IndexMap for the ith celltype of dimension dim.
std::shared_ptr< const common::IndexMap >	index_map (int dim) const
	Get the IndexMap that described the parallel distribution of the mesh entities.
std::vector< std::shared_ptr< const common::IndexMap > >	index_maps (std::int8_t dim) const
std::shared_ptr< const graph::AdjacencyList< std::int32_t > >	connectivity (int d0, int d1) const
	Return connectivity from entities of dimension d0 to entities of dimension d1. Assumes only one entity type per dimension.
std::shared_ptr< const graph::AdjacencyList< std::int32_t > >	connectivity (std::pair< std::int8_t, std::int8_t > d0, std::pair< std::int8_t, std::int8_t > d1) const
	Return the connectivity from entities of topological dimension d0 to dimension d1. The entity type, and incident entity type are each described by a pair (dim, index). The index within a topological dimension dim, is that of the cell type given in entity_types(dim).
void	set_connectivity (std::shared_ptr< graph::AdjacencyList< std::int32_t > > c, int d0, int d1)
	Set connectivity for given pair of topological dimensions.
void	set_connectivity (std::shared_ptr< graph::AdjacencyList< std::int32_t > > c, std::pair< std::int8_t, std::int8_t > d0, std::pair< std::int8_t, std::int8_t > d1)
	Set connectivity for given pair of entity types, defined by dimension and index, as listed in entity_types(). General version for mixed topology. Connectivity from d0 to d1.
const std::vector< std::uint32_t > &	get_cell_permutation_info () const
	Returns the permutation information.
const std::vector< std::uint8_t > &	get_facet_permutations () const
	Get the numbers that encode the number of permutations to apply to facets.
CellType	cell_type () const
	Cell type.
std::vector< CellType >	entity_types (std::int8_t dim) const
	Get the entity types in the topology for a given dimension.
std::int32_t	create_entities (int dim)
	Create entities of given topological dimension.
void	create_connectivity (int d0, int d1)
	Create connectivity between given pair of dimensions, d0 / -> d1.
void	create_entity_permutations ()
	Compute entity permutations and reflections.
const std::vector< std::int32_t > &	interprocess_facets () const
	List of inter-process facets.
const std::vector< std::int32_t > &	interprocess_facets (std::int8_t index) const
	List of inter-process facets, if facet topology has been computed, for the facet type in Topology::entity_types identified by index.
MPI_Comm	comm () const

Public Attributes
std::vector< std::vector< std::int64_t > >	original_cell_index
	Original cell index for each cell type.

Detailed Description

Topology stores the topology of a mesh, consisting of mesh entities and connectivity (incidence relations for the mesh entities).

A mesh entity e may be identified globally as a pair e = (dim, i), where dim is the topological dimension and i is the index of the entity within that topological dimension.

Todo

Rework memory management and associated API. Currently, there is no clear caching policy implemented and no way of discarding cached data.

Constructor & Destructor Documentation

Topology() [1/2]

Topology	(	MPI_Comm	comm,
		CellType	cell_type )

Empty Topology constructor.

Parameters

comm	MPI communicator
cell_type	Type of cell

Topology() [2/2]

Topology	(	MPI_Comm	comm,
		const std::vector< CellType > &	cell_type )

Create empty mesh topology with multiple cell types.

Parameters

comm	MPI communicator
cell_type	List of cell types

Warning

Experimental

Member Function Documentation

cell_type()

mesh::CellType cell_type

(

)

const

Cell type.

Returns

Cell type that the topology is for

comm()

MPI_Comm comm

(

)

const

Mesh MPI communicator

Returns

The communicator on which the topology is distributed

connectivity() [1/2]

std::shared_ptr< const graph::AdjacencyList< std::int32_t > > connectivity	(	int	d0,
		int	d1 ) const

Return connectivity from entities of dimension d0 to entities of dimension d1. Assumes only one entity type per dimension.

Parameters

[in]	d0
[in]	d1

Returns

The adjacency list that for each entity of dimension d0 gives the list of incident entities of dimension d1. Returns nullptr if connectivity has not been computed.

connectivity() [2/2]

std::shared_ptr< const graph::AdjacencyList< std::int32_t > > connectivity	(	std::pair< std::int8_t, std::int8_t >	d0,
		std::pair< std::int8_t, std::int8_t >	d1 ) const

Return the connectivity from entities of topological dimension d0 to dimension d1. The entity type, and incident entity type are each described by a pair (dim, index). The index within a topological dimension dim, is that of the cell type given in entity_types(dim).

Parameters

d0	Pair of (topological dimension of entities, index of "entity type" within topological dimension)
d1	Pair of (topological dimension of indicent entities, index of incident "entity type" within topological dimension)

Returns

AdjacencyList of connectivity from entity type in d0 to entity types in d1, or nullptr if not yet computed.

create_connectivity()

void create_connectivity	(	int	d0,
		int	d1 )

Create connectivity between given pair of dimensions, d0 / -> d1.

Parameters

[in]	d0	Topological dimension
[in]	d1	Topological dimension

create_entities()

std::int32_t create_entities

(

int

dim

)

Create entities of given topological dimension.

Parameters

[in]

dim

Topological dimension

Returns

Number of newly created entities, returns -1 if entities already existed

entity_types()

std::vector< CellType > entity_types

(

std::int8_t

dim

)

const

Get the entity types in the topology for a given dimension.

Parameters

dim	Topological dimension

Returns

List of entity types

get_facet_permutations()

const std::vector< std::uint8_t > & get_facet_permutations

(

)

const

Get the numbers that encode the number of permutations to apply to facets.

The permutations are encoded so that:

• n % 2 gives the number of reflections to apply
• n // 2 gives the number of rotations to apply

The data is stored in a flattened 2D array, so that data[cell_index * / facets_per_cell + facet_index] contains the facet with index facet_index of the cell with index cell_index.

Returns

The encoded permutation info

Note

An exception is raised if the permutations have not been computed

index_map()

std::shared_ptr< const common::IndexMap > index_map

(

int

dim

)

const

Get the IndexMap that described the parallel distribution of the mesh entities.

Parameters

[in]

dim

Topological dimension

Returns

Index map for the entities of dimension dim. Returns nullptr if index map has not been set.

index_maps()

std::vector< std::shared_ptr< const common::IndexMap > > index_maps

(

std::int8_t

dim

)

const

Parameters

dim	Topological dimension

Warning

Experimental

Returns

List of index maps, one for each cell type

interprocess_facets() [1/2]

const std::vector< std::int32_t > & interprocess_facets

(

)

const

List of inter-process facets.

"Inter-process" facets are facets that are connected (1) to a cell that is owned by the calling process (rank) and (2) to a cell that is owned by another process.

Precondition

Inter-process facets are available only if facet topology has been computed.

interprocess_facets() [2/2]

const std::vector< std::int32_t > & interprocess_facets

(

std::int8_t

index

)

const

List of inter-process facets, if facet topology has been computed, for the facet type in Topology::entity_types identified by index.

Parameters

index

Index of facet type

set_connectivity() [1/2]

void set_connectivity	(	std::shared_ptr< graph::AdjacencyList< std::int32_t > >	c,
		int	d0,
		int	d1 )

Set connectivity for given pair of topological dimensions.

Todo

Merge with set_index_map

set_connectivity() [2/2]

void set_connectivity	(	std::shared_ptr< graph::AdjacencyList< std::int32_t > >	c,
		std::pair< std::int8_t, std::int8_t >	d0,
		std::pair< std::int8_t, std::int8_t >	d1 )

Set connectivity for given pair of entity types, defined by dimension and index, as listed in entity_types(). General version for mixed topology. Connectivity from d0 to d1.

Parameters

c	Connectivity AdjacencyList
d0	Pair of (topological dimension of entities, index of "entity type" within topological dimension)
d1	Pair of (topological dimension of indicent entities, index of incident "entity type" within topological dimension)

Warning

Experimental

set_index_map() [1/2]

void set_index_map	(	int	dim,
		std::shared_ptr< const common::IndexMap >	map )

Set the IndexMap for dimension dim.

Todo

Merge with set_connectivity

Warning

This is experimental and likely to change

set_index_map() [2/2]

void set_index_map	(	std::int8_t	dim,
		std::int8_t	i,
		std::shared_ptr< const common::IndexMap >	map )

Set the IndexMap for the ith celltype of dimension dim.

Todo

Merge with set_connectivity

Warning

This is experimental and likely to change

Parameters

dim	Topological dimension
i	Index of cell type within dimension dim. Cell types for each dimension can be obtained with entity_types(dim).
map	Map to set

---

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

• /__w/dolfinx/dolfinx/cpp/dolfinx/mesh/Topology.h
• /__w/dolfinx/dolfinx/cpp/dolfinx/mesh/Topology.cpp