Package org.tweetyproject.graphs

Class HyperGraph<T extends Node>

java.lang.Object

org.tweetyproject.graphs.HyperGraph<T>

Type Parameters:

T - A Node

All Implemented Interfaces:

Iterable<T>, GeneralGraph<T>, Graph<T>

public class HyperGraph<T extends Node>
extends Object
implements Graph<T>

This class implements a simple directed hypergraph

Author:

Sebastian Franke, Matthias Thimm

Field Summary

Fields inherited from interface org.tweetyproject.graphs.Graph

IGNORE_SELFLOOPS, INVERT_SELFLOOPS, REMOVE_SELFLOOPS

Constructor Summary

Constructors

Constructor	Description
HyperGraph()	constructor

Method Summary

Modifier and Type	Method	Description
boolean	add(GeneralEdge<T> edge)	Adds the given edge to this graph.
boolean	add(HyperDirEdge<T> edge)	Add Edge.
boolean	add(T node)	Adds the given node to this graph.
boolean	areAdjacent(Node a, Node b)	Returns "true" iff the two nodes are connected by a directed edge from a to b or an undirected edge.
boolean	contains(Object obj)	Returns "true" when this graph contains the given node or edge.
boolean	existsDirectedPath(HyperGraph<T> hyperGraph, T node1, T node2)	Checks if there is a direct path from node 1 to node 2
boolean	existsDirectedPath(T node1, T node2)	Checks whether there is a (directed) path from node1 to node2.
Matrix	getAdjacencyMatrix()	Returns the adjacency matrix of this graph (the order of the nodes is the same as returned by "iterator()").
Collection<T>	getChildren(Set<T> node)	Return the children of the node
Collection<T>	getChildren(Node node)	Returns the set of children (node connected via an undirected edge or a directed edge where the given node is the parent) of the given node.
HyperGraph<T>	getComplementGraph(int selfloops)	Returns the complement graph of this graph, i.e.
HyperDirEdge<T>	getDirEdge(Set<T> node1, Node b)	Get a directed edge.
Edge<T>	getEdge(Node a, Node b)	Returns the corresponding edge (a,b) if a and b are adjacent.
Collection<HyperDirEdge<T>>	getEdges()	Returns the edges of this graph.
Collection<T>	getNeighbors(Node node)	Returns the set of neighbors of the given node.
Collection<T>	getNodes()	Returns the nodes of this graph.
int	getNumberOfEdges()	Returns the number of edges in this graph.
int	getNumberOfNodes()	Returns the number of nodes in this graph.
Collection<T>	getParents(Node node)	returns all parents without taking indivdual attacks into account
HyperGraph<T>	getRestriction(Collection<T> nodes)	Returns a copy of this graph that contains only the specified nodes and all corresponding edges between them.
Collection<Collection<T>>	getStronglyConnectedComponents()	Returns the strongly connected components of this graph.
Collection<Graph<T>>	getSubgraphs()	Returns the set of sub graphs of this graph.
Collection<Graph<T>>	getSubgraphs(HyperGraph<T> g)	Returns the set of sub graphs of the given graph.
boolean	hasSelfLoops()	Returns "true" iff the graph has a self loop (an edge from a node to itself).
boolean	isWeightedGraph()	Checks whether this graph only contains weighted edges.
Iterator<T>	iterator()
Set<Set<T>>	powerSet(Set<T> originalSet)	Return a powerset.
String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Details

HyperGraph

public HyperGraph()

constructor

Method Details

add

public boolean add(T node)

Description copied from interface: Graph

Adds the given node to this graph.

Specified by:

add in interface Graph<T extends Node>

Parameters:

node - some node.

Returns:

"true" iff the edge has been added successfully.

add

public boolean add(HyperDirEdge<T> edge)

Add Edge. Return whether the operation was successful

Parameters:

edge - an edge

Returns:

whether the operation was successful

getNodes

public Collection<T> getNodes()

Description copied from interface: Graph

Returns the nodes of this graph.

Specified by:

getNodes in interface GeneralGraph<T extends Node>

Specified by:

getNodes in interface Graph<T extends Node>

Returns:

the nodes of this graph.

getNumberOfNodes

public int getNumberOfNodes()

Description copied from interface: Graph

Returns the number of nodes in this graph.

Specified by:

getNumberOfNodes in interface Graph<T extends Node>

Returns:

the number of nodes in this graph.

getNumberOfEdges

public int getNumberOfEdges()

Description copied from interface: Graph

Returns the number of edges in this graph.

Specified by:

getNumberOfEdges in interface Graph<T extends Node>

Returns:

the number of edges in this graph.

areAdjacent

public boolean areAdjacent(Node a,
 Node b)

Description copied from interface: Graph

Returns "true" iff the two nodes are connected by a directed edge from a to b or an undirected edge.

Specified by:

areAdjacent in interface Graph<T extends Node>

Parameters:

a - some node

b - some node

Returns:

"true" iff the two nodes are connected by a directed edge from a to b or an undirected edge.

getEdge

public Edge<T> getEdge(Node a,
 Node b)

Description copied from interface: Graph

Returns the corresponding edge (a,b) if a and b are adjacent. Otherwise it returns null.

Specified by:

getEdge in interface Graph<T extends Node>

Parameters:

a - some node

b - some node

Returns:

the edge (a,b) or null.

getDirEdge

public HyperDirEdge<T> getDirEdge(Set<T> node1,
 Node b)

Get a directed edge.

Parameters:

node1 - a set of nodes (attacker)

b - a node (attacked)

Returns:

a directed Hyper Edge

getEdges

public Collection<HyperDirEdge<T>> getEdges()

Description copied from interface: Graph

Returns the edges of this graph.

Specified by:

getEdges in interface GeneralGraph<T extends Node>

Specified by:

getEdges in interface Graph<T extends Node>

Returns:

the edges of this graph.

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Graph<T extends Node>

Specified by:

iterator in interface Iterable<T extends Node>

contains

public boolean contains(Object obj)

Description copied from interface: Graph

Returns "true" when this graph contains the given node or edge.

Specified by:

contains in interface Graph<T extends Node>

Parameters:

obj - an object

Returns:

"true" if this graph contains the given node or edge.

getChildren

public Collection<T> getChildren(Node node)

Description copied from interface: Graph

Returns the set of children (node connected via an undirected edge or a directed edge where the given node is the parent) of the given node.

Specified by:

getChildren in interface Graph<T extends Node>

Parameters:

node - some node (must be in the graph).

Returns:

the set of children of the given node.

getChildren

public Collection<T> getChildren(Set<T> node)

Return the children of the node

Parameters:

node - a node

Returns:

the children of the node

getParents

public Collection<T> getParents(Node node)

returns all parents without taking indivdual attacks into account

Specified by:

getParents in interface Graph<T extends Node>

Parameters:

node - some node (must be in the graph).

Returns:

the set of parents of the given node.

existsDirectedPath

public boolean existsDirectedPath(HyperGraph<T> hyperGraph,
 T node1,
 T node2)

Checks if there is a direct path from node 1 to node 2

Parameters:

hyperGraph - a hypergraph

node1 - 1st node

node2 - 2nd node

Returns:

checks if there is a direct path from node 1 to node 2

existsDirectedPath

public boolean existsDirectedPath(T node1,
 T node2)

Description copied from interface: Graph

Checks whether there is a (directed) path from node1 to node2.

Specified by:

existsDirectedPath in interface Graph<T extends Node>

Parameters:

node1 - some node.

node2 - some node.

Returns:

"true" if there is a directed path from node1 to node2.

getNeighbors

public Collection<T> getNeighbors(Node node)

Description copied from interface: Graph

Returns the set of neighbors of the given node.

Specified by:

getNeighbors in interface Graph<T extends Node>

Parameters:

node - some node (must be in the graph).

Returns:

the set of neighbors of the given node.

getAdjacencyMatrix

public Matrix getAdjacencyMatrix()

Description copied from interface: Graph

Returns the adjacency matrix of this graph (the order of the nodes is the same as returned by "iterator()").

Specified by:

getAdjacencyMatrix in interface Graph<T extends Node>

Returns:

the adjacency matrix of this graph

powerSet

public Set<Set<T>> powerSet(Set<T> originalSet)

Return a powerset.

Parameters:

originalSet - original set

Returns:

the powerset of @param originalSet

getComplementGraph

public HyperGraph<T> getComplementGraph(int selfloops)

Description copied from interface: Graph

Returns the complement graph of this graph, i.e. the graph on the same set of vertices as this graph that connects two vertices v and w with an edge if and only if v and w are not connected in this graph.

Specified by:

getComplementGraph in interface Graph<T extends Node>

Parameters:

selfloops - Indicates how to deal with selfloops:
IGNORE_SELFLOOPS - ignore self loops (don't add and don't remove)
INVERT_SELFLOOPS - deal with self loops like ordinary edges (add if not present and remove if present)
REMOVE_SELFLOOPS - simple remove self loops, but don't add new ones.

Returns:

the complement graph of this graph.

getStronglyConnectedComponents

public Collection<Collection<T>> getStronglyConnectedComponents()

Description copied from interface: Graph

Returns the strongly connected components of this graph. A set of nodes is strongly connected, if there is a path from each node to each other. A set of nodes is called strongly connected component if it is strongly connected and maximal with respect to set inclusion.

Specified by:

getStronglyConnectedComponents in interface Graph<T extends Node>

Returns:

the strongly connected components of this graph.

getSubgraphs

public Collection<Graph<T>> getSubgraphs()

Description copied from interface: Graph

Returns the set of sub graphs of this graph.

Specified by:

getSubgraphs in interface Graph<T extends Node>

Returns:

the set of sub graphs of this graph.

getSubgraphs

public Collection<Graph<T>> getSubgraphs(HyperGraph<T> g)

Returns the set of sub graphs of the given graph.

Parameters:

g - a graph

Returns:

the set of sub graphs of the given graph.

getRestriction

public HyperGraph<T> getRestriction(Collection<T> nodes)

Description copied from interface: GeneralGraph

Returns a copy of this graph that contains only the specified nodes and all corresponding edges between them.

This method generates a subgraph (or restricted graph) from the current graph by including only the given nodes and the edges that connect them. The returned graph is a new instance and does not modify the original graph.

Specified by:

getRestriction in interface GeneralGraph<T extends Node>

Parameters:

nodes - a collection of nodes to be included in the restricted graph.

Returns:

a `GeneralGraph` object representing the restricted graph.

hasSelfLoops

public boolean hasSelfLoops()

Description copied from interface: Graph

Returns "true" iff the graph has a self loop (an edge from a node to itself).

Specified by:

hasSelfLoops in interface Graph<T extends Node>

Returns:

"true" iff the graph has a self loop (an edge from a node to itself).

isWeightedGraph

public boolean isWeightedGraph()

Description copied from interface: Graph

Checks whether this graph only contains weighted edges.

Specified by:

isWeightedGraph in interface Graph<T extends Node>

Returns:

"true" if all edges are weighted in this graph.

add

public boolean add(GeneralEdge<T> edge)

Description copied from interface: Graph

Adds the given edge to this graph. If at least one of the nodes the given edge connects is not in the graph, an illegal argument exception is thrown.

Specified by:

add in interface Graph<T extends Node>

Parameters:

edge - some edge.

Returns:

"true" iff the edge has been added successfully.

toString

public String toString()

Specified by:

toString in interface Graph<T extends Node>

Overrides:

toString in class Object