edu.stanford.multiagent.gamer.graphs
Class Graph

java.lang.Object
  |
  +--edu.stanford.multiagent.gamer.ParameterizedObject
        |
        +--edu.stanford.multiagent.gamer.graphs.Graph

Direct Known Subclasses:

ALGraph, AMGraph

public abstract class Graph

extends ParameterizedObject

An abstract base class for graph implementations. Note that currently nodes are assumed to be consecutive, starting at 0, and that this class must be updated, if node removal is desired.

Field Summary

protected int	nEdges
protected int	nNodes
protected java.util.HashMap	nodeData
protected static Parameters.ParamInfo	pReflexEdges
protected static Parameters.ParamInfo	pSymEdges

Fields inherited from class edu.stanford.multiagent.gamer.ParameterizedObject

parameters

Constructor Summary

protected

Graph() Constructor.

Method Summary

abstract void	addEdge(int s, int t) Adds a new edge to the graph between nodes s and t.
abstract void	addEdge(int s, int t, java.lang.Object data) Adds a new edge to the graph between nodes s and t and sets the edge data for this edge.
abstract void	addNode() Adds a new node to the graph.
abstract boolean	areNeighbours(int from, int to) Checks if two nodes are neighbours, i.e.
abstract edu.stanford.multiagent.gamer.graphs.Edge	getEdge(int s, int t) Gets an Edge.
abstract java.util.Iterator	getEdges(int from) Returns an iterator over the outgoing edges from a node.
protected abstract java.lang.String	getGraphHelp() Returns a help information string about the particular graph, does not include parameter information.
java.lang.String	getHelp() Returns the help string with information about the graph class and the parameters taken by the class.
int	getNEdges() Returns the number of edges in the graph.
abstract java.util.Iterator	getNeighbours(int from) Returns an iterator over a node's neighbours.
int	getNNodes() Returns the number of vertices in the graph.
java.lang.Object	getNodeData(int n) Returns any data that is being stored at a node.
abstract boolean	hasSymEdges() Returns true if the graph is symmetric, i.e.
void	initialize() Initializes the graph structure using preset parameter values.
abstract boolean	reflexEdgesOk() Returns true if reflexive edges are allowed in the graph.
abstract void	removeEdge(edu.stanford.multiagent.gamer.graphs.Edge e) Removes an edge from the graph.
abstract void	removeEdge(int s, int t) Removes an edge from the graph.
abstract void	setEdgeData(int s, int t, java.lang.Object data) Sets the edge data for an already existing edge.
void	setNodeData(int n, java.lang.Object data) Sets node data.

Methods inherited from class edu.stanford.multiagent.gamer.ParameterizedObject

checkParameters, doGenerate, getBooleanParameter, getDescription, getDoubleParameter, getLongParameter, getParamDescription, getParameter, getParameters, getStringParameter, randomizeParameters, setParameter, setParameter, setParameters, setParameters

Methods inherited from class java.lang.Object

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

Field Detail

nEdges

protected int nEdges

nNodes

protected int nNodes

nodeData

protected java.util.HashMap nodeData

pSymEdges

protected static Parameters.ParamInfo pSymEdges

pReflexEdges

protected static Parameters.ParamInfo pReflexEdges

Constructor Detail

Graph

protected Graph()
         throws java.lang.Exception

Constructor. Currently only one version is available and it does not take parameters.

Method Detail

initialize

public void initialize()
                throws java.lang.Exception

Initializes the graph structure using preset parameter values.

Overrides:

initialize in class ParameterizedObject

Throws:

java.lang.Exception

getHelp

public java.lang.String getHelp()

Returns the help string with information about the graph class and the parameters taken by the class.

Specified by:

getHelp in class ParameterizedObject

getGraphHelp

protected abstract java.lang.String getGraphHelp()

Returns a help information string about the particular graph, does not include parameter information.

getNEdges

public int getNEdges()

Returns the number of edges in the graph.

getNNodes

public int getNNodes()

Returns the number of vertices in the graph.

getNodeData

public java.lang.Object getNodeData(int n)

Returns any data that is being stored at a node.

Parameters:

n - the index of the node

setNodeData

public void setNodeData(int n,
                        java.lang.Object data)

Sets node data.

Parameters:

n - the index of the node

data - the data to be stored at the node

addNode

public abstract void addNode()

Adds a new node to the graph.

addEdge

public abstract void addEdge(int s,
                             int t)

Adds a new edge to the graph between nodes s and t.

Parameters:

s - index of first node

t - index of second node

addEdge

public abstract void addEdge(int s,
                             int t,
                             java.lang.Object data)

Adds a new edge to the graph between nodes s and t and sets the edge data for this edge.

Parameters:

s - index of first node

t - index of second node

data - data to be stored on this edge

setEdgeData

public abstract void setEdgeData(int s,
                                 int t,
                                 java.lang.Object data)

Sets the edge data for an already existing edge.

Parameters:

s - index of the first node on the edge

t - index of the second node on the egde

data - data to be stored on the edge

removeEdge

public abstract void removeEdge(int s,
                                int t)

Removes an edge from the graph.

Parameters:

s - index of the first node on the edge

t - index of the second node on the edge

removeEdge

public abstract void removeEdge(edu.stanford.multiagent.gamer.graphs.Edge e)

Removes an edge from the graph.

Parameters:

e - the edge to be removed

getEdge

public abstract edu.stanford.multiagent.gamer.graphs.Edge getEdge(int s,
                                                                  int t)

Gets an Edge.

Parameters:

s - index of the first node on the edge

t - index of the second node on the edge

areNeighbours

public abstract boolean areNeighbours(int from,
                                      int to)

Checks if two nodes are neighbours, i.e. if there exists an edge from the first node to the second. Note that the order of nodes specified does matter for directed graphs.

Parameters:

from - index of the node at which the edge begins

to - index of the node at which the egde ends

getNeighbours

public abstract java.util.Iterator getNeighbours(int from)

Returns an iterator over a node's neighbours.

Parameters:

from - index of the node

getEdges

public abstract java.util.Iterator getEdges(int from)

Returns an iterator over the outgoing edges from a node.

Parameters:

from - index of the node

hasSymEdges

public abstract boolean hasSymEdges()

Returns true if the graph is symmetric, i.e. if it must be the case that for every edge from node a to node b there also exists an edge from node b to node a.

reflexEdgesOk

public abstract boolean reflexEdgesOk()

Returns true if reflexive edges are allowed in the graph.