edu.columbia.cs.coms4701.search.informed
Interface HeuristicFunction<K extends AgentAction,S extends AgentState,P extends SearchProblem<K,S>>


public interface HeuristicFunction<K extends AgentAction,S extends AgentState,P extends SearchProblem<K,S>>

A problem-specific function h(n) = the estimated cost of the cheapest path from node n to a goal node.

Heuristic functions have one formal constraint: if n is a goal node, h(n) = 0.

A heuristic function is consistent or monotonic if, for every node n and every successor n' generated by any action a, the estimated cost of reaching the goal from n is no greater than the step cost of getting to n' plus the estimated cost of reaching the goal from n'.

Implementations should presumably be customized to a particular type of problem.

Version:
0.1

User: aaron Date: Sep 11, 2006 Time: 5:16:02 PM

Author:
aaron@cs
See Also:
"Russell & Norvig pp95,99,105-110."

Method Summary
 double estimate(SearchNode<K,S> theNode)
          Estimates the cost from the given node to the closest goal node.
 

Method Detail

estimate

double estimate(SearchNode<K,S> theNode)
Estimates the cost from the given node to the closest goal node.

If the given node *is* a goal node, should return zero.

Parameters:
theNode -
Returns:
estimated cost from this node to a goal node.