Class BstarSquaredDB

java.lang.Object

algorithm.BstarSquaredDB

All Implemented Interfaces:

SearchAlgorithm

public class BstarSquaredDB
extends Object
implements SearchAlgorithm

A B*² implementation which uses Disprove-Best B* at the first-level search only.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	BstarSquaredDB.L1Position<P extends IGamePosition<P>>

Nested classes/interfaces inherited from interface algorithm.SearchAlgorithm

SearchAlgorithm.Limits, SearchAlgorithm.SearchResult<N extends GameTreeNode<N,P>, P extends IGamePosition<P>>, SearchAlgorithm.SearchWithTable, SearchAlgorithm.SearchWithTree

Constructor Summary

Constructors

Constructor	Description
BstarSquaredDB(double effort_ratio, StrategyFunction L1_strategyFunction)	Uses the default StrategyFunction.PROVEBEST strategy function for L2 search.
BstarSquaredDB(double effort_ratio, StrategyFunction... strategyFunctions)	The first evaluation function provided corresponds to the function used by the first-level search.

Method Summary

Modifier and Type	Method	Description
void	expectIncorrectBounds(boolean set)	defaults to false
<P extends IGamePosition<P>> SearchAlgorithm.SearchResult<?,P>	search(P root, Duration time_limit, SearchAlgorithm.Limits space_limit, MetricKeeper... metrics)	Initiates the search of the provided game tree with a given time limit and spatial limit.
(package private) void	setLevel(int newLevel)

Methods inherited from class java.lang.Object

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

Methods inherited from interface algorithm.SearchAlgorithm

search, search, search

Constructor Details

BstarSquaredDB

public BstarSquaredDB(double effort_ratio,
 StrategyFunction... strategyFunctions)

The first evaluation function provided corresponds to the function used by the first-level search. The number of strategy functions provided corresponds to the number of levels of search, with a minimum of two.

Parameters:

effort_ratio - The effort ratio of the Disprove-Best B* engine at the first-level search. Typically set between 1 and 2 divided by the branching factor of the tree.

strategyFunctions - The list of strategy functions to apply at the root of a leveled search, including the first-level search.

BstarSquaredDB

public BstarSquaredDB(double effort_ratio,
 StrategyFunction L1_strategyFunction)

Uses the default StrategyFunction.PROVEBEST strategy function for L2 search.

Parameters:

L1_strategyFunction - The strategy function to be used for L1 search.

Method Details

expectIncorrectBounds

public void expectIncorrectBounds(boolean set)

defaults to false

Parameters:

set -

setLevel

void setLevel(int newLevel)

search

public <P extends IGamePosition<P>>
SearchAlgorithm.SearchResult<?,P> search(P root,
 Duration time_limit,
 SearchAlgorithm.Limits space_limit,
 MetricKeeper... metrics)

Description copied from interface: SearchAlgorithm

Initiates the search of the provided game tree with a given time limit and spatial limit.

Specified by:

search in interface SearchAlgorithm

Type Parameters:

P - The type of IGamePosition which represents the type of game to be searched

Parameters:

root - root of the tree to be searched

time_limit - maximum time spent in the algorithm

space_limit - maximum node expansions, evaluations, and nodes saved in memory used by the algorithm

metrics - an array of MetricKeeper objects to keep track of evaluations, expansions, and node storage performed during the search, can be empty

Returns:

result from the search