Dune::Amg::MatrixGraph< M > Class Template Reference

The (undirected) graph of a matrix. More...

#include <dune/istl/paamg/graph.hh>

Classes
class	EdgeIteratorT
	Iterator over all edges starting from a vertex. More...
class	VertexIteratorT
	The vertex iterator type of the graph. More...

Public Types
typedef M	Matrix
	The type of the matrix we are a graph for.
typedef std::remove_const< M >::type	MutableMatrix
	The mutable type of the matrix we are a graph for.
typedef M::block_type	Weight
	The type of the weights.
typedef M::size_type	VertexDescriptor
	The vertex descriptor. More...
typedef std::ptrdiff_t	EdgeDescriptor
	The edge descriptor. More...
typedef EdgeIteratorT< const MatrixGraph< Matrix > >	ConstEdgeIterator
	The constant edge iterator type.
typedef EdgeIteratorT< MatrixGraph< Matrix > >	EdgeIterator
	The mutable edge iterator type.
typedef VertexIteratorT< const MatrixGraph< Matrix > >	ConstVertexIterator
	The constant vertex iterator type.
typedef VertexIteratorT< MatrixGraph< Matrix > >	VertexIterator
	The mutable vertex iterator type.

Public Member Functions
	MatrixGraph (Matrix &matrix)
	Constructor. More...
	~MatrixGraph ()
	Destructor.
VertexIterator	begin ()
	Get an iterator over the vertices. More...
VertexIterator	end ()
	Get an iterator over the vertices. More...
ConstVertexIterator	begin () const
	Get an iterator over the vertices. More...
ConstVertexIterator	end () const
	Get an iterator over the vertices. More...
EdgeIterator	beginEdges (const VertexDescriptor &source)
	Get an iterator over the edges starting at a vertex. More...
EdgeIterator	endEdges (const VertexDescriptor &source)
	Get an iterator over the edges starting at a vertex. More...
ConstEdgeIterator	beginEdges (const VertexDescriptor &source) const
	Get an iterator over the edges starting at a vertex. More...
ConstEdgeIterator	endEdges (const VertexDescriptor &source) const
	Get an iterator over the edges starting at a vertex. More...
Matrix &	matrix ()
	Get the underlying matrix. More...
const Matrix &	matrix () const
	Get the underlying matrix. More...
std::size_t	noVertices () const
	Get the number of vertices in the graph.
VertexDescriptor	maxVertex () const
	Get the maximal vertex descriptor. More...
std::size_t	noEdges () const
	Get the number of edges in the graph.
EdgeDescriptor	findEdge (const VertexDescriptor &source, const VertexDescriptor &target) const
	Find the descriptor of an edge. More...

Detailed Description

template<class M>
class Dune::Amg::MatrixGraph< M >

The (undirected) graph of a matrix.

The graph of a sparse matrix essentially describes the sparsity pattern (nonzero entries) of a matrix. It is assumed that the underlying sparsity pattern is symmetric, i.e if entry a_ij is present in the storage scheme of the matrix (i.e. nonzero) so is a_ji.

The matrix entries can be accessed as weights of the vertices and edges.

Member Typedef Documentation

EdgeDescriptor

template<class M >

typedef std::ptrdiff_t Dune::Amg::MatrixGraph< M >::EdgeDescriptor

The edge descriptor.

Each edge is identifies by exactly one descriptor.

VertexDescriptor

template<class M >

typedef M::size_type Dune::Amg::MatrixGraph< M >::VertexDescriptor

The vertex descriptor.

Each descriptor describes exactly one vertex.

Constructor & Destructor Documentation

MatrixGraph()

template<class M >

Dune::Amg::MatrixGraph< M >::MatrixGraph

(

Matrix &

matrix

)

Constructor.

Parameters

matrix

The matrix we are a graph for.

Member Function Documentation

begin() [1/2]

template<class M >

VertexIterator Dune::Amg::MatrixGraph< M >::begin

(

)

Get an iterator over the vertices.

Returns

A vertex Iterator positioned at the first vertex.

begin() [2/2]

template<class M >

ConstVertexIterator Dune::Amg::MatrixGraph< M >::begin

(

)

const

Get an iterator over the vertices.

Returns

A vertex Iterator positioned at the first vertex.

beginEdges() [1/2]

template<class M >

EdgeIterator Dune::Amg::MatrixGraph< M >::beginEdges

(

const VertexDescriptor &

source

)

Get an iterator over the edges starting at a vertex.

Parameters

source

The vertex where the edges should start.

Returns

An edge iterator positioned at the first edge starting from vertex source.

beginEdges() [2/2]

template<class M >

ConstEdgeIterator Dune::Amg::MatrixGraph< M >::beginEdges

(

const VertexDescriptor &

source

)

const

Get an iterator over the edges starting at a vertex.

Parameters

source

The vertex where the edges should start.

Returns

An edge iterator positioned at the first edge starting from vertex source.

end() [1/2]

template<class M >

VertexIterator Dune::Amg::MatrixGraph< M >::end

(

)

Get an iterator over the vertices.

Returns

A vertex Iterator positioned behind the last vertex.

end() [2/2]

template<class M >

ConstVertexIterator Dune::Amg::MatrixGraph< M >::end

(

)

const

Get an iterator over the vertices.

Returns

A vertex Iterator positioned behind the last vertex.

endEdges() [1/2]

template<class M >

EdgeIterator Dune::Amg::MatrixGraph< M >::endEdges

(

const VertexDescriptor &

source

)

Get an iterator over the edges starting at a vertex.

Parameters

source

The vertex where the edges should start.

Returns

An edge iterator positioned behind the last edge starting from vertex source.

endEdges() [2/2]

template<class M >

ConstEdgeIterator Dune::Amg::MatrixGraph< M >::endEdges

(

const VertexDescriptor &

source

)

const

Get an iterator over the edges starting at a vertex.

Parameters

source

The vertex where the edges should start.

Returns

An edge iterator positioned behind the last edge starting from vertex source.

findEdge()

template<class M >

EdgeDescriptor Dune::Amg::MatrixGraph< M >::findEdge	(	const VertexDescriptor &	source,
		const VertexDescriptor &	target
	)		const

Find the descriptor of an edge.

Parameters

source	The source vertex of the edge we search for.
target	The target vertex of the edge we search for.

Returns

The edge we found or numeric_limits<EdgeIterator>::max() if it does not exist.

matrix() [1/2]

template<class M >

Matrix& Dune::Amg::MatrixGraph< M >::matrix

(

)

Get the underlying matrix.

Returns

The matrix of the graph.

matrix() [2/2]

template<class M >

const Matrix& Dune::Amg::MatrixGraph< M >::matrix

(

)

const

Get the underlying matrix.

Returns

The matrix of the graph.

maxVertex()

template<class M >

VertexDescriptor Dune::Amg::MatrixGraph< M >::maxVertex

(

)

const

Get the maximal vertex descriptor.

Returns

The minimum value v such that for all vertices w in the graph w<v holds.

---

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

• dune/istl/paamg/graph.hh