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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.FloatChromosome;
11  import net.bmahe.genetics4j.core.combination.ChromosomeCombinator;
12  import net.bmahe.genetics4j.core.spec.AbstractEAConfiguration;
13  
14  public class FloatChromosomeSinglePointCrossover<T extends Comparable<T>> implements ChromosomeCombinator<T> {
15  
16  	private final RandomGenerator randomGenerator;
17  
18  	public FloatChromosomeSinglePointCrossover(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(FloatChromosome.class, chromosome1);
30  		Validate.isInstanceOf(FloatChromosome.class, chromosome2);
31  		Validate.isTrue(chromosome1.getNumAlleles() == chromosome2.getNumAlleles());
32  
33  		final int alleleSplit = randomGenerator.nextInt(chromosome1.getNumAlleles());
34  
35  		final var floatChromosome1 = (FloatChromosome) chromosome1;
36  		final var floatChromosome2 = (FloatChromosome) chromosome2;
37  
38  		final int numAlleles = chromosome1.getNumAlleles();
39  		final float[] firstChildValues = new float[numAlleles];
40  		final float[] secondChildValues = new float[numAlleles];
41  
42  		for (int i = 0; i < numAlleles; i++) {
43  
44  			if (i < alleleSplit) {
45  				firstChildValues[i] = floatChromosome1.getAllele(i);
46  				secondChildValues[i] = floatChromosome2.getAllele(i);
47  			} else {
48  				firstChildValues[i] = floatChromosome2.getAllele(i);
49  				secondChildValues[i] = floatChromosome1.getAllele(i);
50  			}
51  		}
52  
53  		/**
54  		 * TODO Should the min/max values be extended based on the lowest/highest values?
55  		 */
56  		final float minValue = floatChromosome1.getMinValue();
57  		final float maxValue = floatChromosome2.getMaxValue();
58  
59  		return List.of(
60  				new FloatChromosome(numAlleles, minValue, maxValue, firstChildValues),
61  					new FloatChromosome(numAlleles, minValue, maxValue, secondChildValues));
62  	}
63  }