Package se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm

Class TerminateByDiversityRelStDev

java.lang.Object

se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm.TerminationCriterionBase

se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm.TerminateByDiversityRelStDev

All Implemented Interfaces:

TerminationCriterion

public class TerminateByDiversityRelStDev
extends TerminationCriterionBase

Diversity-based termination criterion: Termination is triggered when the relative standard deviation of the cost values within the current generation is below a given threshold or the N-th generation is reached.

Field Summary

Fields

Modifier and Type	Field	Description
protected final double	relStDevThreshold

Fields inherited from class se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm.TerminationCriterionBase

nrGenerations

Constructor Summary

Constructors

Constructor	Description
TerminateByDiversityRelStDev(double relStDevThreshold, LogicalPlan plan)

Method Summary

Modifier and Type	Method	Description
static TerminationCriterionFactory	getFactory(double relStDevThreshold)
boolean	readyToTerminate(Generation currentGeneration, List<Generation> allPreviousGenerations)	Returns true if this termination criterion has been reached with the current generation.

Methods inherited from class se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.evolutionaryAlgorithm.TerminationCriterionBase

calcFactorial, countNumOfOps

Methods inherited from class java.lang.Object

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

Field Details

relStDevThreshold

protected final double relStDevThreshold

Constructor Details

TerminateByDiversityRelStDev

public TerminateByDiversityRelStDev(double relStDevThreshold,
 LogicalPlan plan)

Method Details

getFactory

public static TerminationCriterionFactory getFactory(double relStDevThreshold)

readyToTerminate

public boolean readyToTerminate(Generation currentGeneration,
 List<Generation> allPreviousGenerations)

Description copied from interface: TerminationCriterion

Returns true if this termination criterion has been reached with the current generation.

Parameters:

currentGeneration - the current generation for which the termination criterion is test

allPreviousGenerations - a list of all previous generations, in the order in which they have been created