Package fr.uga.pddl4j.heuristics.state

Class GraphHeuristic

java.lang.Object

fr.uga.pddl4j.heuristics.AbstractHeuristic

fr.uga.pddl4j.heuristics.state.AbstractStateHeuristic

fr.uga.pddl4j.heuristics.state.GraphHeuristic

All Implemented Interfaces:

Heuristic, PlanningGraphHeuristic, StateHeuristic, Serializable

Direct Known Subclasses:

SetLevel, SumMutex

public abstract class GraphHeuristic
extends AbstractStateHeuristic
implements PlanningGraphHeuristic

This abstract class implements the basic methods used by all heuristics based on the computation of a planning graph with mutual exclusions.

This implementation is based on the implementation of the STAN planner proposed D. Long and M. Fox. To have more information about this implementation see D. Long, M. Fox (1999). Efficient Implementation of the Plan Graph in STAN. Journal of Artificial Intelligence Research, 10(1):87-115.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface fr.uga.pddl4j.heuristics.state.StateHeuristic

StateHeuristic.Name

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	GraphHeuristic(Problem problem)	Creates a new RelaxedGraphHeuristic heuristic.

Method Summary

Modifier and Type	Method	Description
protected int	expandPlanningGraph(State state)	This method creates the relaxed planning graph from a specified initial state.
protected int	getSumValue()	Computes the sum heuristic.
protected boolean	isGoalReachable()	Return true if the goal is reached in the last proposition level of the expanded planning graph.
protected void	setGoal(Condition goal)	Set the goal of the problem to solve in order to compute the heuristic.

Methods inherited from class fr.uga.pddl4j.heuristics.state.AbstractStateHeuristic

getActions, getGoal, getRevelantFacts, isAdmissible, setAdmissible

Methods inherited from class java.lang.Object

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

Methods inherited from interface fr.uga.pddl4j.heuristics.state.StateHeuristic

estimate, estimate, isAdmissible

Constructor Details

GraphHeuristic

protected GraphHeuristic(Problem problem)

Creates a new RelaxedGraphHeuristic heuristic.

Parameters:

problem - the problem to be solved.

Method Details

setGoal

protected final void setGoal(Condition goal)

Set the goal of the problem to solve in order to compute the heuristic.

Overrides:

setGoal in class AbstractStateHeuristic

Parameters:

goal - the goal.

expandPlanningGraph

protected final int expandPlanningGraph(State state)

This method creates the relaxed planning graph from a specified initial state.

Parameters:

state - the initial state of the relaxed planning graph.

Returns:

the level of the graph built.

getSumValue

protected final int getSumValue()

Computes the sum heuristic.

Returns:

the sum heuristic value.

See Also:

Sum

isGoalReachable

protected final boolean isGoalReachable()

Return true if the goal is reached in the last proposition level of the expanded planning graph.

Returns:

true if the goal is reached in the last proposition level of the expanded planning graph; false otherwise.