io.jenetics.ext.moea

Class MOEA

java.lang.Object

io.jenetics.ext.moea.MOEA

public final class MOEA
extends Object

Collectors for collecting final pareto-set for multi-objective optimization.

final Problem<double[], DoubleGene, Vec<double[]>> problem = Problem.of( v -> Vec.of(v[0]*cos(v[1]), v[0]*sin(v[1])), Codecs.ofVector( DoubleRange.of(0, 1), DoubleRange.of(0, 2*PI) ) ); final Engine<DoubleGene, Vec<double[]>> engine = Engine.builder(problem) .alterers( new Mutator<>(0.1), new MeanAlterer<>()) .offspringSelector(new TournamentSelector<>(2)) .survivorsSelector(UFTournamentSelector.vec()) .build(); final ISeq<Phenotype<DoubleGene, Vec<double[]>>> result = engine.stream() .limit(Limits.byFixedGeneration(50)) .collect(MOEA.toParetoSet());

Since:

4.1

Version:

4.1

Author:

Franz Wilhelmstötter

Method Summary

Modifier and Type	Method and Description
static <G extends Gene<?,G>,T,V extends Vec<T>> Collector<EvolutionResult<G,V>,?,ISeq<Phenotype<G,V>>>	toParetoSet() Collector of Phenotype objects, who's (multi-objective) fitness value is part of the pareto front.
static <G extends Gene<?,G>,T,V extends Vec<T>> Collector<EvolutionResult<G,V>,?,ISeq<Phenotype<G,V>>>	toParetoSet(IntRange size) Collector of Phenotype objects, who's (multi-objective) fitness value is part of the pareto front.
static <G extends Gene<?,G>,C extends Comparable<? super C>> Collector<EvolutionResult<G,C>,?,ISeq<Phenotype<G,C>>>	toParetoSet(IntRange size, Comparator<? super C> dominance, ElementComparator<? super C> comparator, ElementDistance<? super C> distance, ToIntFunction<? super C> dimension) Collector of Phenotype objects, who's (multi-objective) fitness value is part of the pareto front.

Methods inherited from class java.lang.Object

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

Method Detail

toParetoSet

public static <G extends Gene<?,G>,T,V extends Vec<T>> Collector<EvolutionResult<G,V>,?,ISeq<Phenotype<G,V>>> toParetoSet()

Collector of Phenotype objects, who's (multi-objective) fitness value is part of the pareto front.

Type Parameters:

G - the gene type

T - the array type, e.g. double[]

V - the multi object result type vector

Returns:

the pareto set collector

Throws:

IllegalArgumentException - if the minimal pareto set size is smaller than one

toParetoSet

public static <G extends Gene<?,G>,T,V extends Vec<T>> Collector<EvolutionResult<G,V>,?,ISeq<Phenotype<G,V>>> toParetoSet(IntRange size)

Collector of Phenotype objects, who's (multi-objective) fitness value is part of the pareto front.

Type Parameters:

G - the gene type

T - the array type, e.g. double[]

V - the multi object result type vector

Parameters:

size - the allowed size range of the returned pareto set. If the size of the pareto set is bigger than size.getMax(), during the collection, it is reduced to size.getMin(). Pareto set elements which are close to each other are removed firsts.

Returns:

the pareto set collector

Throws:

NullPointerException - if one the size is null

IllegalArgumentException - if the minimal pareto set size is smaller than one

toParetoSet

public static <G extends Gene<?,G>,C extends Comparable<? super C>> Collector<EvolutionResult<G,C>,?,ISeq<Phenotype<G,C>>> toParetoSet(IntRange size,
                                                                                                                                       Comparator<? super C> dominance,
                                                                                                                                       ElementComparator<? super C> comparator,
                                                                                                                                       ElementDistance<? super C> distance,
                                                                                                                                       ToIntFunction<? super C> dimension)

Collector of Phenotype objects, who's (multi-objective) fitness value is part of the pareto front.

Type Parameters:

G - the gene type

C - the multi object result vector. E.g. Vec<double[]>

Parameters:

size - the allowed size range of the returned pareto set. If the size of the pareto set is bigger than size.getMax(), during the collection, it is reduced to size.getMin(). Pareto set elements which are close to each other are removed firsts.

dominance - the pareto dominance measure of the fitness result type C

comparator - the comparator of the elements of the vector type C

distance - the distance function of two elements of the vector type C

dimension - the dimensionality of the result vector C. Usually Vec::length.

Returns:

the pareto set collector

Throws:

NullPointerException - if one the arguments is null

IllegalArgumentException - if the minimal pareto set size is smaller than one

See Also:

toParetoSet(IntRange)