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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
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package org.apache.commons.math4.genetics;
import org.apache.commons.math4.exception.DimensionMismatchException;
import org.apache.commons.math4.exception.MathIllegalArgumentException;
import org.apache.commons.math4.genetics.BinaryChromosome;
import org.apache.commons.math4.genetics.Chromosome;
import org.apache.commons.math4.genetics.ChromosomePair;
import org.apache.commons.math4.genetics.CrossoverPolicy;
import org.apache.commons.math4.genetics.CycleCrossover;
import org.junit.Assert;
import org.junit.Test;
public class CycleCrossoverTest {
@Test
public void testCrossoverExample() {
// taken from http://www.rubicite.com/Tutorials/GeneticAlgorithms/CrossoverOperators/CycleCrossoverOperator.aspx
final Integer[] p1 = new Integer[] { 8, 4, 7, 3, 6, 2, 5, 1, 9, 0 };
final Integer[] p2 = new Integer[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
final DummyListChromosome p1c = new DummyListChromosome(p1);
final DummyListChromosome p2c = new DummyListChromosome(p2);
final CrossoverPolicy cp = new CycleCrossover<Integer>();
final ChromosomePair pair = cp.crossover(p1c, p2c);
final Integer[] c1 = ((DummyListChromosome) pair.getFirst()).getRepresentation().toArray(new Integer[p1.length]);
final Integer[] c2 = ((DummyListChromosome) pair.getSecond()).getRepresentation().toArray(new Integer[p2.length]);
final Integer[] c1e = new Integer[] { 8, 1, 2, 3, 4, 5, 6, 7, 9, 0 };
final Integer[] c2e = new Integer[] { 0, 4, 7, 3, 6, 2, 5, 1, 8, 9 };
Assert.assertArrayEquals(c1e, c1);
Assert.assertArrayEquals(c2e, c2);
}
@Test
public void testCrossoverExample2() {
// taken from http://www.scribd.com/doc/54206412/32/Cycle-crossover
final Integer[] p1 = new Integer[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
final Integer[] p2 = new Integer[] { 9, 3, 7, 8, 2, 6, 5, 1, 4};
final DummyListChromosome p1c = new DummyListChromosome(p1);
final DummyListChromosome p2c = new DummyListChromosome(p2);
final CrossoverPolicy cp = new CycleCrossover<Integer>();
final ChromosomePair pair = cp.crossover(p1c, p2c);
final Integer[] c1 = ((DummyListChromosome) pair.getFirst()).getRepresentation().toArray(new Integer[p1.length]);
final Integer[] c2 = ((DummyListChromosome) pair.getSecond()).getRepresentation().toArray(new Integer[p2.length]);
final Integer[] c1e = new Integer[] { 1, 3, 7, 4, 2, 6, 5, 8, 9 };
final Integer[] c2e = new Integer[] { 9, 2, 3, 8, 5, 6, 7, 1, 4 };
Assert.assertArrayEquals(c1e, c1);
Assert.assertArrayEquals(c2e, c2);
}
@Test
public void testCrossover() {
final Integer[] p1 = new Integer[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
final Integer[] p2 = new Integer[] { 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 };
final DummyListChromosome p1c = new DummyListChromosome(p1);
final DummyListChromosome p2c = new DummyListChromosome(p2);
final CrossoverPolicy cp = new CycleCrossover<Integer>(true);
for (int i = 0; i < 20; i++) {
final ChromosomePair pair = cp.crossover(p1c, p2c);
final Integer[] c1 = ((DummyListChromosome) pair.getFirst()).getRepresentation().toArray(new Integer[p1.length]);
final Integer[] c2 = ((DummyListChromosome) pair.getSecond()).getRepresentation().toArray(new Integer[p2.length]);
int index = 0;
// Determine if it is in the same spot as in the first parent, if
// not it comes from the second parent.
for (final Integer j : c1) {
if (!p1[index].equals(j)) {
Assert.assertEquals(j, p2[index]);
} else {
Assert.assertEquals(j, p1[index]);
}
index++;
}
// Same as above only for the second parent.
index = 0;
for (final Integer k : c2) {
if (p2[index] != k) {
Assert.assertEquals(k, p1[index]);
} else {
Assert.assertEquals(k, p2[index]);
}
index++;
}
}
}
@Test(expected = DimensionMismatchException.class)
public void testCrossoverDimensionMismatchException() {
final Integer[] p1 = new Integer[] { 1, 0, 1, 0, 0, 1, 0, 1, 1 };
final Integer[] p2 = new Integer[] { 0, 1, 1, 0, 1 };
final BinaryChromosome p1c = new DummyBinaryChromosome(p1);
final BinaryChromosome p2c = new DummyBinaryChromosome(p2);
final CrossoverPolicy cp = new CycleCrossover<Integer>();
cp.crossover(p1c, p2c);
}
@Test(expected = MathIllegalArgumentException.class)
public void testCrossoverInvalidFixedLengthChromosomeFirst() {
final Integer[] p1 = new Integer[] { 1, 0, 1, 0, 0, 1, 0, 1, 1 };
final BinaryChromosome p1c = new DummyBinaryChromosome(p1);
final Chromosome p2c = new Chromosome() {
@Override
public double fitness() {
// Not important
return 0;
}
};
final CrossoverPolicy cp = new CycleCrossover<Integer>();
cp.crossover(p1c, p2c);
}
@Test(expected = MathIllegalArgumentException.class)
public void testCrossoverInvalidFixedLengthChromosomeSecond() {
final Integer[] p1 = new Integer[] { 1, 0, 1, 0, 0, 1, 0, 1, 1 };
final BinaryChromosome p2c = new DummyBinaryChromosome(p1);
final Chromosome p1c = new Chromosome() {
@Override
public double fitness() {
// Not important
return 0;
}
};
final CrossoverPolicy cp = new CycleCrossover<Integer>();
cp.crossover(p1c, p2c);
}
}