Module org.jgrapht.opt

Package org.jgrapht.opt.graph.sparse.specifics

Class IncomingNoReindexSparseDirectedSpecifics

java.lang.Object

org.jgrapht.opt.graph.sparse.specifics.NoIncomingNoReindexSparseDirectedSpecifics

org.jgrapht.opt.graph.sparse.specifics.IncomingNoReindexSparseDirectedSpecifics

All Implemented Interfaces:

SparseGraphSpecifics

public class IncomingNoReindexSparseDirectedSpecifics
extends NoIncomingNoReindexSparseDirectedSpecifics

Specifics for a sparse directed graph which does not re-index the edges and supports incoming edges. No reindexing means that the edges are numbered in increasing order using the order that the user loads the edges. Support for incoming edges is provided but is initialized lazily the first time the user accessed a corresponding method.

Author:

Dimitrios Michail

Field Summary

Fields

Modifier and Type	Field	Description
protected CSRBooleanMatrix	inIncidenceMatrix	Incidence matrix with incoming edges

Fields inherited from class org.jgrapht.opt.graph.sparse.specifics.NoIncomingNoReindexSparseDirectedSpecifics

NO_INCOMING, outIncidenceMatrix, source, target, UNMODIFIABLE

Constructor Summary

Constructors

Constructor	Description
IncomingNoReindexSparseDirectedSpecifics(int numVertices, int numEdges, Supplier<Stream<Pair<Integer,Integer>>> edges, boolean lazyIncomingEdges)	Create a new graph from an edge list.

Method Summary

Modifier and Type	Method	Description
long	degreeOf(Integer vertex)	Returns the degree of the specified vertex.
Set<Integer>	edgesOf(Integer vertex)	Returns a set of all edges touching the specified vertex.
Set<Integer>	incomingEdgesOf(Integer vertex)	Returns a set of all edges incoming into the specified vertex.
long	inDegreeOf(Integer vertex)	Returns the "in degree" of the specified vertex.
protected void	indexIncomingEdges()	Build the index for the incoming edges.

Methods inherited from class org.jgrapht.opt.graph.sparse.specifics.NoIncomingNoReindexSparseDirectedSpecifics

edgesCount, getAllEdges, getEdge, getEdgeSource, getEdgeTarget, getType, outDegreeOf, outgoingEdgesOf, verticesCount

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.jgrapht.opt.graph.sparse.specifics.SparseGraphSpecifics

assertEdgeExist, assertVertexExist, containsEdge, containsVertex, edgeSet, getEdgeWeight, setEdgeWeight, vertexSet

Field Details

inIncidenceMatrix

protected CSRBooleanMatrix inIncidenceMatrix

Incidence matrix with incoming edges

Constructor Details

IncomingNoReindexSparseDirectedSpecifics

public IncomingNoReindexSparseDirectedSpecifics(int numVertices,
 int numEdges,
 Supplier<Stream<Pair<Integer,Integer>>> edges,
 boolean lazyIncomingEdges)

Create a new graph from an edge list.

Parameters:

numVertices - the number of vertices

numEdges - the number of edges

edges - a supplier of an edge stream

lazyIncomingEdges - whether to lazily support incoming edge traversals, only if actually needed by the user

Method Details

degreeOf

public long degreeOf(Integer vertex)

Description copied from interface: SparseGraphSpecifics

Returns the degree of the specified vertex.

A degree of a vertex in an undirected graph is the number of edges touching that vertex. Edges with same source and target vertices (self-loops) are counted twice.

In directed graphs this method returns the sum of the "in degree" and the "out degree".

Specified by:

degreeOf in interface SparseGraphSpecifics

Overrides:

degreeOf in class NoIncomingNoReindexSparseDirectedSpecifics

Parameters:

vertex - vertex whose degree is to be calculated.

Returns:

the degree of the specified vertex.

edgesOf

public Set<Integer> edgesOf(Integer vertex)

Description copied from interface: SparseGraphSpecifics

Returns a set of all edges touching the specified vertex. If no edges are touching the specified vertex returns an empty set.

Specified by:

edgesOf in interface SparseGraphSpecifics

Overrides:

edgesOf in class NoIncomingNoReindexSparseDirectedSpecifics

Parameters:

vertex - the vertex for which a set of touching edges is to be returned.

Returns:

a set of all edges touching the specified vertex.

inDegreeOf

public long inDegreeOf(Integer vertex)

Description copied from interface: SparseGraphSpecifics

Returns the "in degree" of the specified vertex.

The "in degree" of a vertex in a directed graph is the number of inward directed edges from that vertex. See http://mathworld.wolfram.com/Indegree.html.

In the case of undirected graphs this method returns the number of edges touching the vertex. Edges with same source and target vertices (self-loops) are counted twice.

Specified by:

inDegreeOf in interface SparseGraphSpecifics

Overrides:

inDegreeOf in class NoIncomingNoReindexSparseDirectedSpecifics

Parameters:

vertex - vertex whose degree is to be calculated.

Returns:

the degree of the specified vertex.

incomingEdgesOf

public Set<Integer> incomingEdgesOf(Integer vertex)

Description copied from interface: SparseGraphSpecifics

Returns a set of all edges incoming into the specified vertex.

In the case of undirected graphs this method returns all edges touching the vertex, thus, some of the returned edges may have their source and target vertices in the opposite order.

Specified by:

incomingEdgesOf in interface SparseGraphSpecifics

Overrides:

incomingEdgesOf in class NoIncomingNoReindexSparseDirectedSpecifics

Parameters:

vertex - the vertex for which the list of incoming edges to be returned.

Returns:

a set of all edges incoming into the specified vertex.

indexIncomingEdges

protected void indexIncomingEdges()

Build the index for the incoming edges.