MOEA Framework 2.12
API Specification

org.moeaframework.algorithm
Class PESA2

java.lang.Object
  extended by org.moeaframework.algorithm.AbstractAlgorithm
      extended by org.moeaframework.algorithm.AbstractEvolutionaryAlgorithm
          extended by org.moeaframework.algorithm.PESA2
All Implemented Interfaces:
Algorithm, EvolutionaryAlgorithm

public class PESA2
extends AbstractEvolutionaryAlgorithm

Implementation of the Pareto Envelope-based Selection Algorithm (PESA2).

References:

  1. Corne, D. W., N. R. Jerram, J. D. Knowles, and M. J. Oates (2001). PESA-II: Region-based Selection in Evolutionary Multiobjective Optimization. Proceedings of the Genetic and Evolutionary Computation Conference (GECCO 2001), pp. 283-290.
  2. Corne, D. W., J. D. Knowles, and M. J. Oates (2000). The Pareto Envelope-based Selection Algorithm for Multiobjective Optimization. Parallel Problem Solving from Nature PPSN VI, pp. 839-848.


Nested Class Summary
 class PESA2.RegionBasedSelection
          Region-based selection.
 
Field Summary
protected  Map<Integer,List<Solution>> gridMap
          A mapping from grid index to the solutions occupying that grid index.
protected  Selection selection
          The selection operator.
protected  Variation variation
          The variation operator.
 
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
PESA2(Problem problem, Variation variation, Initialization initialization, int bisections, int archiveSize)
          Constructs a new PESA2 instance.
 
Method Summary
protected  Map<Integer,List<Solution>> createGridMap()
          Returns a mapping from grid index to the solutions occupying that grid index.
 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 iterate()
          Performs one iteration of the algorithm.
 
Methods inherited from class org.moeaframework.algorithm.AbstractEvolutionaryAlgorithm
getPopulation, 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, isTerminated, step, terminate
 

Field Detail

selection

protected final Selection selection
The selection operator.


variation

protected final Variation variation
The variation operator.


gridMap

protected Map<Integer,List<Solution>> gridMap
A mapping from grid index to the solutions occupying that grid index. This enables PESA2's region-based selection.

Constructor Detail

PESA2

public PESA2(Problem problem,
             Variation variation,
             Initialization initialization,
             int bisections,
             int archiveSize)
Constructs a new PESA2 instance.

Parameters:
problem - the problem
variation - the mutation operator
initialization - the initialization operator
bisections - the number of bisections in the adaptive grid archive
archiveSize - the capacity of the adaptive grid archive
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

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

createGridMap

protected Map<Integer,List<Solution>> createGridMap()
Returns a mapping from grid index to the solutions occupying that grid index. The key is the grid index, and the value is the list of solutions occupying that index.

Returns:
a mapping from grid index to the solutions occupying that grid index

MOEA Framework 2.12
API Specification

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Licensed under the GNU Lesser General Public License.
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