org.moeaframework.algorithm
Class PAES

java.lang.Object
  org.moeaframework.algorithm.AbstractAlgorithm
      org.moeaframework.algorithm.AbstractEvolutionaryAlgorithm
          org.moeaframework.algorithm.PAES

All Implemented Interfaces:

Algorithm, EvolutionaryAlgorithm

public class PAES
extends AbstractEvolutionaryAlgorithm

Implementation of the (1+1) Pareto Archived Evolution Strategy (PAES). PAES uses an adaptive grid archive to maintain a diverse set of solutions.

References:

1. Knowles, J.D. and D. W. Corne (1999). The Pareto Archived Evolution Strategy: A New Baseline Algorithm for Pareto Multiobjective Optimisation. In Proceedings of the 1999 Congress on Evolutionary Computation (CEC'99), pp. 98-105.

Field Summary

Fields inherited from class org.moeaframework.algorithm.AbstractEvolutionaryAlgorithm

archive, initialization, population

Fields inherited from class org.moeaframework.algorithm.AbstractAlgorithm

initialized, numberOfEvaluations, problem, terminated

Constructor Summary

PAES(Problem problem, Variation variation, int bisections, int archiveSize)
Constructs a new PAES instance.

Method Summary

AdaptiveGridArchive	getArchive() Returns the current non-dominated archive of the best solutions generated by this evolutionary algorithm, or null if no archive is used.
protected void	initialize() Performs any initialization that is required by this algorithm.
protected void	iterate() Performs one iteration of the algorithm.
Solution	test(Solution parent, Solution offspring) The test procedure to determine which solution, the parent or offspring, moves on to the next generation.

Methods inherited from class org.moeaframework.algorithm.AbstractEvolutionaryAlgorithm

getPopulation, getResult, getState, setState

Methods inherited from class org.moeaframework.algorithm.AbstractAlgorithm

evaluate, evaluateAll, evaluateAll, finalize, getNumberOfEvaluations, getProblem, isInitialized, isTerminated, step, terminate

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.moeaframework.core.Algorithm

evaluate, getNumberOfEvaluations, getProblem, isTerminated, step, terminate

Constructor Detail

PAES

public PAES(Problem problem,
            Variation variation,
            int bisections,
            int archiveSize)

Constructs a new PAES instance.

Parameters:

problem - the problem

variation - the mutation operator

bisections - the number of bisections in the adaptive grid archive

archiveSize - the capacity of the adaptive grid archive

Throws:

IllegalArgumentExceptio - if the variation operator requires more than one parent

Method Detail

getArchive

public AdaptiveGridArchive getArchive()

Description copied from interface: EvolutionaryAlgorithm

Returns the current non-dominated archive of the best solutions generated by this evolutionary algorithm, or null if no archive is used.

Specified by:

getArchive in interface EvolutionaryAlgorithm

Overrides:

getArchive in class AbstractEvolutionaryAlgorithm

Returns:

the current non-dominated archive of the best solutions generated by this evolutionary algorithm, or null if no archive is used

initialize

protected void initialize()

Description copied from class: AbstractAlgorithm

Performs any initialization that is required by this algorithm. This method is called automatically by the first invocation of AbstractAlgorithm.step(), but may also be called manually prior to any invocations of step. Implementations should always invoke super.initialize() to ensure the hierarchy is initialized correctly.

Overrides:

initialize in class AbstractEvolutionaryAlgorithm

test

public Solution test(Solution parent,
                     Solution offspring)

The test procedure to determine which solution, the parent or offspring, moves on to the next generation. The solution in a lower density region in the archive is returned.

Parameters:

parent - the parent solution

offspring - the offspring solution

Returns:

the solution moving on to the next genreation

iterate

protected void iterate()

Description copied from class: AbstractAlgorithm

Performs one iteration of the algorithm. This method should be overridden by implementations to perform each logical iteration of the algorithm.

Specified by:

iterate in class AbstractAlgorithm