org.eclipse.viatra.dse.api.strategy.impl

Class BestFirstStrategy

java.lang.Object

org.eclipse.viatra.dse.api.strategy.impl.BestFirstStrategy

All Implemented Interfaces:

IStrategy

public class BestFirstStrategy
extends java.lang.Object
implements IStrategy

This exploration strategy eventually explorers the whole design space but goes in the most promising directions first, based on the Fitness. There are a few parameter to tune such as

• maximum depth
• continue the exploration from a state that satisfies the hard objectives (the default that it will backtrack),
• whether to continue the exploration from the newly explored state if it is at least equally good than the previous one or only if it is better (default is "at least equally good").

Constructor Summary

Constructors

Constructor and Description
BestFirstStrategy() Creates a new best-first search algorithm without depth limit.
BestFirstStrategy(int maxDepth) Creates a new best-first search algorithm with depth limit.

Method Summary

Modifier and Type	Method and Description
BestFirstStrategy	continueIfHardObjectivesFulfilled()
void	explore() This method explores the design space as the implementation specifies.
BestFirstStrategy	goOnOnlyIfFitnessIsBetter()
void	initStrategy(ThreadContext context) Initializes the strategy with a specific ThreadContext.
void	interruptStrategy() The implementation of this interface should be ready to be interrupted.

Methods inherited from class java.lang.Object

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

Constructor Detail

BestFirstStrategy

public BestFirstStrategy()

Creates a new best-first search algorithm without depth limit.

BestFirstStrategy

public BestFirstStrategy(int maxDepth)

Creates a new best-first search algorithm with depth limit.

Parameters:

maxDepth - A negative maxDepth means no depth limit, zero means the checking of the initial state.

Method Detail

continueIfHardObjectivesFulfilled

public BestFirstStrategy continueIfHardObjectivesFulfilled()

goOnOnlyIfFitnessIsBetter

public BestFirstStrategy goOnOnlyIfFitnessIsBetter()

initStrategy

public void initStrategy(ThreadContext context)

Description copied from interface: IStrategy

Initializes the strategy with a specific ThreadContext.

Specified by:

initStrategy in interface IStrategy

Parameters:

context - The context.

explore

public void explore()

Description copied from interface: IStrategy

This method explores the design space as the implementation specifies. It will be called only once, hence the exploration loop is run by the implementation. The termination condition is also specified by the implementation and when it returns the exploration thread will be disposed.

Specified by:

explore in interface IStrategy

interruptStrategy

public void interruptStrategy()

Description copied from interface: IStrategy

The implementation of this interface should be ready to be interrupted. If this method is called, the IStrategy.explore() method should return ASAP. This method is also called by the SolutionStore class if enough solutions are found.

Specified by:

interruptStrategy in interface IStrategy