org.moeaframework.algorithm
Class NSGAII

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

All Implemented Interfaces:

Algorithm, EpsilonBoxEvolutionaryAlgorithm, EvolutionaryAlgorithm

public class NSGAII
extends AbstractEvolutionaryAlgorithm
implements EpsilonBoxEvolutionaryAlgorithm

Implementation of NSGA-II, with the ability to attach an optional ε-dominance archive.

References:

1. Deb, K. et al. "A Fast Elitist Multi-Objective Genetic Algorithm: NSGA-II." IEEE Transactions on Evolutionary Computation, 6:182-197, 2000.
2. Kollat, J. B., and Reed, P. M. "Comparison of Multi-Objective Evolutionary Algorithms for Long-Term Monitoring Design." Advances in Water Resources, 29(6):792-807, 2006.

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

NSGAII(Problem problem, NondominatedSortingPopulation population, EpsilonBoxDominanceArchive archive, Selection selection, Variation variation, Initialization initialization)
Constructs the NSGA-II algorithm with the specified components.

Method Summary

EpsilonBoxDominanceArchive	getArchive() Returns the current non-dominated archive of the best solutions generated by this evolutionary algorithm, or null if no archive is used.
NondominatedSortingPopulation	getPopulation() Returns the current population of this evolutionary algorithm.
void	iterate() Performs one iteration of the algorithm.

Methods inherited from class org.moeaframework.algorithm.AbstractEvolutionaryAlgorithm

getResult, getState, initialize, 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, getResult, getState, isTerminated, setState, step, terminate

Constructor Detail

NSGAII

public NSGAII(Problem problem,
              NondominatedSortingPopulation population,
              EpsilonBoxDominanceArchive archive,
              Selection selection,
              Variation variation,
              Initialization initialization)

Constructs the NSGA-II algorithm with the specified components.

Parameters:

problem - the problem being solved

population - the population used to store solutions

archive - the archive used to store the result; can be null

selection - the selection operator

variation - the variation operator

initialization - the initialization method

Method Detail

iterate

public 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

getArchive

public EpsilonBoxDominanceArchive 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 EpsilonBoxEvolutionaryAlgorithm

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

getPopulation

public NondominatedSortingPopulation getPopulation()

Description copied from interface: EvolutionaryAlgorithm

Returns the current population of this evolutionary algorithm.

Specified by:

getPopulation in interface EvolutionaryAlgorithm

Overrides:

getPopulation in class AbstractEvolutionaryAlgorithm

Returns:

the current population of this evolutionary algorithm