 java.lang.Object

 org.jgrapht.graph.AbstractGraph<V,E>

 org.jgrapht.graph.GraphDelegator<V,E>

 org.jgrapht.graph.AsUndirectedGraph<V,E>

 Type Parameters:
V
 the graph vertex typeE
 the graph edge type
 All Implemented Interfaces:
Serializable
,Graph<V,E>
public class AsUndirectedGraph<V,E> extends GraphDelegator<V,E> implements Serializable, Graph<V,E>
An undirected view of the backing directed graph specified in the constructor. This graph allows modules to apply algorithms designed for undirected graphs to a directed graph by simply ignoring edge direction. If the backing directed graph is an oriented graph, then the view will be a simple graph; otherwise, it will be a multigraph. Query operations on this graph "read through" to the backing graph. Attempts to add edges will result in anUnsupportedOperationException
, but vertex addition/removal and edge removal are all supported (and immediately reflected in the backing graph).Note that edges returned by this graph's accessors are really just the edges of the underlying directed graph. Since there is no interface distinction between directed and undirected edges, this detail should be irrelevant to algorithms.
This graph does not pass the hashCode and equals operations through to the backing graph, but relies on
Object
'sequals
andhashCode
methods. This graph will be serializable if the backing graph is serializable. Author:
 John V. Sichi
 See Also:
 Serialized Form


Field Summary

Fields inherited from interface org.jgrapht.Graph
DEFAULT_EDGE_WEIGHT


Constructor Summary
Constructors Constructor Description AsUndirectedGraph(Graph<V,E> g)
Constructor for AsUndirectedGraph.

Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description E
addEdge(V sourceVertex, V targetVertex)
Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge.boolean
addEdge(V sourceVertex, V targetVertex, E e)
Adds the specified edge to this graph, going from the source vertex to the target vertex.int
degreeOf(V vertex)
Returns the degree of the specified vertex.Set<E>
getAllEdges(V sourceVertex, V targetVertex)
Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph.E
getEdge(V sourceVertex, V targetVertex)
Returns an edge connecting source vertex to target vertex if such vertices and such edge exist in this graph.GraphType
getType()
Get the graph type.Set<E>
incomingEdgesOf(V vertex)
Returns a set of all edges incoming into the specified vertex.int
inDegreeOf(V vertex)
Returns the "in degree" of the specified vertex.int
outDegreeOf(V vertex)
Returns the "out degree" of the specified vertex.Set<E>
outgoingEdgesOf(V vertex)
Returns a set of all edges outgoing from the specified vertex.String
toString()
Returns a string of the parenthesized pair (V, E) representing this G=(V,E) graph.
Methods inherited from class org.jgrapht.graph.GraphDelegator
addVertex, addVertex, containsEdge, containsVertex, edgeSet, edgesOf, getDelegate, getEdgeSource, getEdgeSupplier, getEdgeTarget, getEdgeWeight, getVertexSupplier, removeEdge, removeEdge, removeVertex, setEdgeWeight, vertexSet

Methods inherited from class org.jgrapht.graph.AbstractGraph
assertVertexExist, containsEdge, equals, hashCode, removeAllEdges, removeAllEdges, removeAllEdges, removeAllVertices, toStringFromSets

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.jgrapht.Graph
addVertex, addVertex, containsEdge, containsEdge, containsVertex, edgeSet, edgesOf, getEdgeSource, getEdgeSupplier, getEdgeTarget, getEdgeWeight, getVertexSupplier, iterables, removeAllEdges, removeAllEdges, removeAllVertices, removeEdge, removeEdge, removeVertex, setEdgeWeight, setEdgeWeight, vertexSet




Constructor Detail

AsUndirectedGraph
public AsUndirectedGraph(Graph<V,E> g)
Constructor for AsUndirectedGraph. Parameters:
g
 the backing directed graph over which an undirected view is to be created. Throws:
IllegalArgumentException
 if the graph is not directed


Method Detail

getAllEdges
public Set<E> getAllEdges(V sourceVertex, V targetVertex)
Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph. If any of the vertices does not exist or isnull
, returnsnull
. If both vertices exist but no edges found, returns an empty set.In undirected graphs, some of the returned edges may have their source and target vertices in the opposite order. In simple graphs the returned set is either singleton set or empty set.
 Specified by:
getAllEdges
in interfaceGraph<V,E>
 Overrides:
getAllEdges
in classGraphDelegator<V,E>
 Parameters:
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge. Returns:
 a set of all edges connecting source vertex to target vertex.

getEdge
public E getEdge(V sourceVertex, V targetVertex)
Returns an edge connecting source vertex to target vertex if such vertices and such edge exist in this graph. Otherwise returnsnull
. If any of the specified vertices isnull
returnsnull
In undirected graphs, the returned edge may have its source and target vertices in the opposite order.

addEdge
public E addEdge(V sourceVertex, V targetVertex)
Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge. Some graphs do not allow edgemultiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, then this method does not change the graph and returnsnull
.The source and target vertices must already be contained in this graph. If they are not found in graph
IllegalArgumentException
is thrown.This method creates the new edge
e
using this graph's edge supplier (seeGraph.getEdgeSupplier()
). For the new edge to be addede
must not be equal to any other edge the graph (even if the graph allows edgemultiplicity). More formally, the graph must not contain any edgee2
such thate2.equals(e)
. If suche2
is found then the newly created edgee
is abandoned, the method leaves this graph unchanged and returnsnull
.If the underlying graph implementation's
Graph.getEdgeSupplier()
returnsnull
, then this method cannot create edges and throws anUnsupportedOperationException
. Specified by:
addEdge
in interfaceGraph<V,E>
 Overrides:
addEdge
in classGraphDelegator<V,E>
 Parameters:
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge. Returns:
 The newly created edge if added to the graph, otherwise
null
.  Throws:
UnsupportedOperationException
 always, since operation is unsupported See Also:
Graph.getEdgeSupplier()

addEdge
public boolean addEdge(V sourceVertex, V targetVertex, E e)
Adds the specified edge to this graph, going from the source vertex to the target vertex. More formally, adds the specified edge,e
, to this graph if this graph contains no edgee2
such thate2.equals(e)
. If this graph already contains such an edge, the call leaves this graph unchanged and returnsfalse
. Some graphs do not allow edgemultiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, then this method does not change the graph and returnsfalse
. If the edge was added to the graph, returnstrue
. Specified by:
addEdge
in interfaceGraph<V,E>
 Overrides:
addEdge
in classGraphDelegator<V,E>
 Parameters:
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge.e
 edge to be added to this graph. Returns:
true
if this graph did not already contain the specified edge. Throws:
UnsupportedOperationException
 always, since operation is unsupported See Also:
Graph.addEdge(Object, Object)
,Graph.getEdgeSupplier()

degreeOf
public int degreeOf(V vertex)
Returns the degree of the specified vertex.

incomingEdgesOf
public Set<E> incomingEdgesOf(V vertex)
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 interfaceGraph<V,E>
 Overrides:
incomingEdgesOf
in classGraphDelegator<V,E>
 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.

inDegreeOf
public int inDegreeOf(V vertex)
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 (selfloops) are counted twice.
 Specified by:
inDegreeOf
in interfaceGraph<V,E>
 Overrides:
inDegreeOf
in classGraphDelegator<V,E>
 Parameters:
vertex
 vertex whose degree is to be calculated. Returns:
 the degree of the specified vertex.

outgoingEdgesOf
public Set<E> outgoingEdgesOf(V vertex)
Returns a set of all edges outgoing from 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:
outgoingEdgesOf
in interfaceGraph<V,E>
 Overrides:
outgoingEdgesOf
in classGraphDelegator<V,E>
 Parameters:
vertex
 the vertex for which the list of outgoing edges to be returned. Returns:
 a set of all edges outgoing from the specified vertex.

outDegreeOf
public int outDegreeOf(V vertex)
Returns the "out degree" of the specified vertex.The "out degree" of a vertex in a directed graph is the number of outward directed edges from that vertex. See http://mathworld.wolfram.com/Outdegree.html.
In the case of undirected graphs this method returns the number of edges touching the vertex. Edges with same source and target vertices (selfloops) are counted twice.
 Specified by:
outDegreeOf
in interfaceGraph<V,E>
 Overrides:
outDegreeOf
in classGraphDelegator<V,E>
 Parameters:
vertex
 vertex whose degree is to be calculated. Returns:
 the degree of the specified vertex.

getType
public GraphType getType()
Get the graph type. The graph type can be used to query for additional metadata such as whether the graph supports directed or undirected edges, selfloops, multiple (parallel) edges, weights, etc.

toString
public String toString()
Returns a string of the parenthesized pair (V, E) representing this G=(V,E) graph. 'V' is the string representation of the vertex set, and 'E' is the string representation of the edge set. Overrides:
toString
in classGraphDelegator<V,E>
 Returns:
 a string representation of this graph.

