1 package net.bmahe.genetics4j.core.combination.singlepointcrossover;
2
3 import java.util.List;
4 import java.util.random.RandomGenerator;
5
6 import org.apache.commons.lang3.Validate;
7
8 import net.bmahe.genetics4j.core.chromosomes.Chromosome;
9 import net.bmahe.genetics4j.core.chromosomes.IntChromosome;
10 import net.bmahe.genetics4j.core.combination.ChromosomeCombinator;
11 import net.bmahe.genetics4j.core.spec.AbstractEAConfiguration;
12
13 public class IntChromosomeSinglePointCrossover<T extends Comparable<T>> implements ChromosomeCombinator<T> {
14
15 private final RandomGenerator randomGenerator;
16
17 public IntChromosomeSinglePointCrossover(final RandomGenerator _randomGenerator) {
18 Validate.notNull(_randomGenerator);
19
20 this.randomGenerator = _randomGenerator;
21 }
22
23 @Override
24 public List<Chromosome> combine(final AbstractEAConfiguration<T> eaConfiguration, final Chromosome chromosome1,
25 final T firstParentFitness, final Chromosome chromosome2, final T secondParentFitness) {
26 Validate.notNull(chromosome1);
27 Validate.notNull(chromosome2);
28 Validate.isInstanceOf(IntChromosome.class, chromosome1);
29 Validate.isInstanceOf(IntChromosome.class, chromosome2);
30 Validate.isTrue(chromosome1.getNumAlleles() == chromosome2.getNumAlleles());
31
32 final int alleleSplit = randomGenerator.nextInt(chromosome1.getNumAlleles());
33
34 final IntChromosome intChromosome1 = (IntChromosome) chromosome1;
35 final IntChromosome intChromosome2 = (IntChromosome) chromosome2;
36
37 final int numAlleles = chromosome1.getNumAlleles();
38 final int[] firstChildValues = new int[numAlleles];
39 final int[] secondChildValues = new int[numAlleles];
40
41 for (int i = 0; i < numAlleles; i++) {
42
43 if (i < alleleSplit) {
44 firstChildValues[i] = intChromosome1.getAllele(i);
45 secondChildValues[i] = intChromosome2.getAllele(i);
46 } else {
47 firstChildValues[i] = intChromosome2.getAllele(i);
48 secondChildValues[i] = intChromosome1.getAllele(i);
49 }
50 }
51
52 return List.of(
53 new IntChromosome(numAlleles, intChromosome1.getMinValue(), intChromosome1.getMaxValue(), firstChildValues),
54 new IntChromosome(numAlleles,
55 intChromosome1.getMinValue(),
56 intChromosome1.getMaxValue(),
57 secondChildValues));
58 }
59 }