dk.deepthought.sidious.planner.graph
Class AStarGraph

java.lang.Object
  dk.deepthought.sidious.planner.graph.AStarGraph

All Implemented Interfaces:

Graph

public final class AStarGraph
extends java.lang.Object
implements Graph

Represents a graph for use with the A-Star algorithm.

Author:

Deepthought

Field Summary

private Vertex	goalVertex The goal vertex of this.
private Heuristic	heuristic The heuristic to be used with this.
private static org.apache.commons.logging.Log	logger The logger of this class.
private SuperLinkID	requesterId The id of the requester.
private RuleEngine	ruleEngine Cached instance of the rule engine.
private Vertex	sourceVertex The source vertex of this.
private java.util.List<Vertex>	vertices The vertices of this.

Constructor Summary

AStarGraph(State sourceState, State goalState, java.util.Collection<Adjustable> adjustables, Heuristic heuristic, SuperLinkID requester)
Constructs an AStarGraph with a start and end-state, and the set adjustables.

Method Summary

(package private) double	calculateCost(State current, State next, Step step) Method returns the calculated cost of getting from current to next.
java.util.Collection<Edge>	getEdges(Vertex v) This method retrieves the edges emanating from the Vertex v.
Vertex	getGoalVertex() Gets the goal Vertex of this Graph.
SuperLinkID	getId() Returns the id of the owner/requester for this graph.
Vertex	getSourceVertex() Gets the source Vertex of this Graph.
(package private) Vertex	getVertexFromState(State state) This method checks if the state is represented by a Vertex in the graph, and returns either the representing vertex or a new vertex, which is added to the graph.
void	setApproximateGoal(Vertex v) Method sets the goalVertex to this vertex if all the goal state descriptors are contained in the input vertex.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

logger

private static final org.apache.commons.logging.Log logger

The logger of this class.

vertices

private final java.util.List<Vertex> vertices

The vertices of this.

sourceVertex

private final Vertex sourceVertex

The source vertex of this.

goalVertex

private Vertex goalVertex

The goal vertex of this. It can be substituted if an approximate goal is set.

heuristic

private final Heuristic heuristic

The heuristic to be used with this.

requesterId

private final SuperLinkID requesterId

The id of the requester.

ruleEngine

private final RuleEngine ruleEngine

Cached instance of the rule engine.

Constructor Detail

AStarGraph

public AStarGraph(State sourceState,
                  State goalState,
                  java.util.Collection<Adjustable> adjustables,
                  Heuristic heuristic,
                  SuperLinkID requester)

Constructs an AStarGraph with a start and end-state, and the set adjustables.

Parameters:

sourceState - the beginning state of any path

goalState - the end state of any path

adjustables - the adjustables of the current requester

heuristic - the heuristic of the graph

requester - the id of the plan requester

Method Detail

getEdges

public java.util.Collection<Edge> getEdges(Vertex v)

This method retrieves the edges emanating from the Vertex v. It does this by calculating the edges and vertices on-the-fly.

Specified by:

getEdges in interface Graph

Parameters:

v - the starting Vertex

Returns:

all edges starting in the specified Vertex

See Also:

Graph.getEdges(dk.deepthought.sidious.planner.graph.Vertex)

calculateCost

double calculateCost(State current,
                     State next,
                     Step step)

Method returns the calculated cost of getting from current to next.

Parameters:

current - the current state

next - the next state

step - the step

Returns:

the cost

getVertexFromState

Vertex getVertexFromState(State state)

This method checks if the state is represented by a Vertex in the graph, and returns either the representing vertex or a new vertex, which is added to the graph.

Parameters:

state - the state

Returns:

the vertex representing the state

getGoalVertex

public Vertex getGoalVertex()

Description copied from interface: Graph

Gets the goal Vertex of this Graph. The goal vertex is defined as the ending point of any path in this graph.

The implementing graph class must guarantee that any preconditions for the goal vertex of the Pathfinder are not violated.

Specified by:

getGoalVertex in interface Graph

Returns:

the goal vertex of this graph

getSourceVertex

public Vertex getSourceVertex()

Description copied from interface: Graph

Gets the source Vertex of this Graph. The source vertex is defined as the starting point of any path in this graph.

The implementing graph class must guarantee that any preconditions for the source vertex of the Pathfinder are not violated.

Specified by:

getSourceVertex in interface Graph

Returns:

the source vertex of this graph

getId

public SuperLinkID getId()

Description copied from interface: Graph

Returns the id of the owner/requester for this graph.

Specified by:

getId in interface Graph

Returns:

the id of the requester

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

setApproximateGoal

public void setApproximateGoal(Vertex v)

Description copied from interface: Graph

Method sets the goalVertex to this vertex if all the goal state descriptors are contained in the input vertex.

Specified by:

setApproximateGoal in interface Graph

Parameters:

v - the approximate goal candidate