burlap.behavior.singleagent.planning.deterministic.informed

Class PrioritizedSearchNode

java.lang.Object

burlap.behavior.singleagent.planning.deterministic.SearchNode

burlap.behavior.singleagent.planning.deterministic.informed.PrioritizedSearchNode

public class PrioritizedSearchNode
extends SearchNode

An extension of the SearchNode class that includes a priority value. Priority is used to represent the "f" function, which in A* is defined to be the sum of the cost to the node and the admissible heuristic from it. The priority is use to order nodes for expansion.

Author:

James MacGlashan

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PrioritizedSearchNode.PSNComparator A class for comparing the priority of two PrioritizedSearchNodes.

Field Summary

Fields

Modifier and Type	Field and Description
double	priority The priority of the node used to order it for expansion.

Fields inherited from class burlap.behavior.singleagent.planning.deterministic.SearchNode

backPointer, generatingAction, s

Constructor Summary

Constructors

Constructor and Description
PrioritizedSearchNode(HashableState s, Action ga, SearchNode bp, double p) Constructs a SearchNode for the input state and priority and sets the generating action and back pointer to the provided elements.
PrioritizedSearchNode(HashableState s, double p) Initializes a PrioritizedSearchNode for a given (hashed) input state and priority value.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
int	hashCode()
void	setAuxInfoTo(PrioritizedSearchNode o) This method rewires the generating node information and priority to that specified in a different PrioritizedSearchNode.

Methods inherited from class java.lang.Object

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

Field Detail

priority

public double priority

The priority of the node used to order it for expansion.

Constructor Detail

PrioritizedSearchNode

public PrioritizedSearchNode(HashableState s,
                             double p)

Initializes a PrioritizedSearchNode for a given (hashed) input state and priority value. The generating action and back pointer will be set to null which is valid for initial states.

Parameters:

s - the hashed input state this node represents.

p - the priority of this node.

PrioritizedSearchNode

public PrioritizedSearchNode(HashableState s,
                             Action ga,
                             SearchNode bp,
                             double p)

Constructs a SearchNode for the input state and priority and sets the generating action and back pointer to the provided elements.

Parameters:

s - the hashed input state this node will represent.

ga - the action that was used to generate s

bp - the search node that contains the previous state from which s was generated.

p - the priority of the node.

Method Detail

setAuxInfoTo

public void setAuxInfoTo(PrioritizedSearchNode o)

This method rewires the generating node information and priority to that specified in a different PrioritizedSearchNode. This method is useful when a better path to this node has been found.

Parameters:

o - the other PrioritizedSearchNode whose generating information and priority should be used.

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class SearchNode

hashCode

public int hashCode()

Overrides:

hashCode in class SearchNode