DoubleChromosomeRandomMutationHandler.java
package net.bmahe.genetics4j.core.mutation.chromosome.randommutation;
import java.util.Arrays;
import java.util.random.RandomGenerator;
import org.apache.commons.lang3.Validate;
import net.bmahe.genetics4j.core.chromosomes.Chromosome;
import net.bmahe.genetics4j.core.chromosomes.DoubleChromosome;
import net.bmahe.genetics4j.core.mutation.chromosome.ChromosomeMutationHandler;
import net.bmahe.genetics4j.core.spec.chromosome.ChromosomeSpec;
import net.bmahe.genetics4j.core.spec.chromosome.DoubleChromosomeSpec;
import net.bmahe.genetics4j.core.spec.mutation.MutationPolicy;
import net.bmahe.genetics4j.core.spec.mutation.RandomMutation;
public class DoubleChromosomeRandomMutationHandler implements ChromosomeMutationHandler<DoubleChromosome> {
private final RandomGenerator randomGenerator;
public DoubleChromosomeRandomMutationHandler(final RandomGenerator _randomGenerator) {
Validate.notNull(_randomGenerator);
this.randomGenerator = _randomGenerator;
}
@Override
public boolean canHandle(final MutationPolicy mutationPolicy, final ChromosomeSpec chromosome) {
Validate.notNull(mutationPolicy);
Validate.notNull(chromosome);
return mutationPolicy instanceof RandomMutation && chromosome instanceof DoubleChromosomeSpec;
}
@Override
public DoubleChromosome mutate(final MutationPolicy mutationPolicy, final Chromosome chromosome) {
Validate.notNull(mutationPolicy);
Validate.notNull(chromosome);
Validate.isInstanceOf(RandomMutation.class, mutationPolicy);
Validate.isInstanceOf(DoubleChromosome.class, chromosome);
final DoubleChromosome doubleChromosome = (DoubleChromosome) chromosome;
final double minValue = doubleChromosome.getMinValue();
final double maxValue = doubleChromosome.getMaxValue();
final double[] newValues = Arrays.copyOf(doubleChromosome.getValues(), doubleChromosome.getNumAlleles());
final int alleleFlipIndex = randomGenerator.nextInt(doubleChromosome.getNumAlleles());
newValues[alleleFlipIndex] = minValue + randomGenerator.nextDouble() * (maxValue - minValue);
return new DoubleChromosome(doubleChromosome.getSize(), minValue, maxValue, newValues);
}
}