1 package net.bmahe.genetics4j.core.combination.singlepointcrossover;
2
3 import java.util.List;
4 import java.util.Objects;
5 import java.util.random.RandomGenerator;
6
7 import org.apache.commons.lang3.Validate;
8
9 import net.bmahe.genetics4j.core.chromosomes.Chromosome;
10 import net.bmahe.genetics4j.core.chromosomes.DoubleChromosome;
11 import net.bmahe.genetics4j.core.combination.ChromosomeCombinator;
12 import net.bmahe.genetics4j.core.spec.AbstractEAConfiguration;
13
14 public class DoubleChromosomeSinglePointCrossover<T extends Comparable<T>> implements ChromosomeCombinator<T> {
15
16 private final RandomGenerator randomGenerator;
17
18 public DoubleChromosomeSinglePointCrossover(final RandomGenerator _randomGenerator) {
19 Objects.requireNonNull(_randomGenerator);
20
21 this.randomGenerator = _randomGenerator;
22 }
23
24 @Override
25 public List<Chromosome> combine(final AbstractEAConfiguration<T> eaConfiguration, final Chromosome chromosome1,
26 final T firstParentFitness, final Chromosome chromosome2, final T secondParentFitness) {
27 Objects.requireNonNull(chromosome1);
28 Objects.requireNonNull(chromosome2);
29 Validate.isInstanceOf(DoubleChromosome.class, chromosome1);
30 Validate.isInstanceOf(DoubleChromosome.class, chromosome2);
31 Validate.isTrue(chromosome1.getNumAlleles() == chromosome2.getNumAlleles());
32
33 final int alleleSplit = randomGenerator.nextInt(chromosome1.getNumAlleles());
34
35 final var doubleChromosome1 = (DoubleChromosome) chromosome1;
36 final var doubleChromosome2 = (DoubleChromosome) chromosome2;
37
38 final int numAlleles = chromosome1.getNumAlleles();
39 final double[] firstChildValues = new double[numAlleles];
40 final double[] secondChildValues = new double[numAlleles];
41
42 for (int i = 0; i < numAlleles; i++) {
43
44 if (i < alleleSplit) {
45 firstChildValues[i] = doubleChromosome1.getAllele(i);
46 secondChildValues[i] = doubleChromosome2.getAllele(i);
47 } else {
48 firstChildValues[i] = doubleChromosome2.getAllele(i);
49 secondChildValues[i] = doubleChromosome1.getAllele(i);
50 }
51 }
52
53
54
55
56 final double minValue = doubleChromosome1.getMinValue();
57 final double maxValue = doubleChromosome2.getMaxValue();
58
59 return List.of(
60 new DoubleChromosome(numAlleles, minValue, maxValue, firstChildValues),
61 new DoubleChromosome(numAlleles, minValue, maxValue, secondChildValues));
62 }
63 }