ec.multiobjective.spea2

Class SPEA2Evaluator

java.lang.Object

ec.Evaluator

ec.simple.SimpleEvaluator

ec.multiobjective.spea2.SPEA2Evaluator

All Implemented Interfaces:

Setup, Singleton, Serializable

public class SPEA2Evaluator
extends SimpleEvaluator

This subclass of SimpleEvaluator evaluates the population, then computes auxiliary fitness data of each subpopulation.

See Also:

Serialized Form

Field Summary

Fields inherited from class ec.simple.SimpleEvaluator

C_AUTO, cloneProblem, MERGE_BEST, MERGE_MEAN, MERGE_MEDIAN, mergeForm, numTests, P_CHUNK_SIZE, P_CLONE_PROBLEM, P_MERGE, P_NUM_TESTS, pool, V_AUTO, V_BEST, V_MEAN, V_MEDIAN

Fields inherited from class ec.Evaluator

masterproblem, P_IAMSLAVE, P_MASTERPROBLEM, p_problem, P_PROBLEM

Constructor Summary

Constructors

Constructor and Description
SPEA2Evaluator()

Method Summary

Methods

Modifier and Type	Method and Description
double[][]	calculateDistances(EvolutionState state, Individual[] inds) Returns a matrix of sum squared distances from each individual to each other individual.
void	computeAuxiliaryData(EvolutionState state, Individual[] inds) Computes the strength of individuals, then the raw fitness (wimpiness) and kth-closest sparsity measure.
void	evaluatePopulation(EvolutionState state) A simple evaluator that doesn't do any coevolutionary evaluation.
(package private) double	orderStatistics(double[] array, int kth, MersenneTwisterFast rng) Returns the kth smallest element in the array.
(package private) int	partition(double[] array, int p, int r)
(package private) int	randomizedPartition(double[] array, int p, int r, MersenneTwisterFast rng)
(package private) double	randomizedSelect(double[] array, int p, int r, int i, MersenneTwisterFast rng)

Methods inherited from class ec.simple.SimpleEvaluator

evalPopChunk, runComplete, setup

Methods inherited from class ec.Evaluator

closeContacts, initializeContacts, reinitializeContacts

Methods inherited from class java.lang.Object

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

Constructor Detail

SPEA2Evaluator

public SPEA2Evaluator()

Method Detail

evaluatePopulation

public void evaluatePopulation(EvolutionState state)

Description copied from class: SimpleEvaluator

A simple evaluator that doesn't do any coevolutionary evaluation. Basically it applies evaluation pipelines, one per thread, to various subchunks of a new population.

Overrides:

evaluatePopulation in class SimpleEvaluator

computeAuxiliaryData

public void computeAuxiliaryData(EvolutionState state,
                        Individual[] inds)

Computes the strength of individuals, then the raw fitness (wimpiness) and kth-closest sparsity measure. Finally, computes the final fitness of the individuals.

calculateDistances

public double[][] calculateDistances(EvolutionState state,
                            Individual[] inds)

Returns a matrix of sum squared distances from each individual to each other individual.

orderStatistics

double orderStatistics(double[] array,
                     int kth,
                     MersenneTwisterFast rng)

Returns the kth smallest element in the array. Note that here k=1 means the smallest element in the array (not k=0). Uses a randomized sorting technique, hence the need for the random number generator.

randomizedSelect

double randomizedSelect(double[] array,
                      int p,
                      int r,
                      int i,
                      MersenneTwisterFast rng)

randomizedPartition

int randomizedPartition(double[] array,
                      int p,
                      int r,
                      MersenneTwisterFast rng)

partition

int partition(double[] array,
            int p,
            int r)