//=============================================================================
// Copyright 2006-2010 Daniel W. Dyer
//
// Licensed 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.
//=============================================================================
package org.uncommons.watchmaker.framework.operators;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.testng.annotations.Test;
import org.uncommons.maths.random.Probability;
import org.uncommons.watchmaker.framework.EvolutionaryOperator;
import org.uncommons.watchmaker.framework.FrameworkTestUtils;
/**
* Unit test for cross-over with integer arrays.
* @author Daniel Dyer
*/
public class IntArrayCrossoverTest
{
@Test
public void testCrossover()
{
EvolutionaryOperator<int[]> crossover = new IntArrayCrossover();
List<int[]> population = new ArrayList<int[]>(4);
population.add(new int[]{1, 2, 3, 4, 5});
population.add(new int[]{6, 7, 8, 9, 10});
population.add(new int[]{11, 12, 13, 14, 15});
population.add(new int[]{16, 17, 18, 19, 20});
Set<Integer> values = new HashSet<Integer>(20);
for (int i = 0; i < 20; i++)
{
population = crossover.apply(population, FrameworkTestUtils.getRNG());
assert population.size() == 4 : "Population size changed after cross-over.";
for (int[] individual : population)
{
assert individual.length == 5 : "Invalid candidate length: " + individual.length;
for (int value : individual)
{
values.add(value);
}
}
// All of the individual elements should still be present, just jumbled up
// between individuals.
assert values.size() == 20 : "Information lost during cross-over.";
values.clear();
}
}
/**
* The {@link IntArrayCrossover} operator is only defined to work on populations
* containing arrays of equal lengths. Any attempt to apply the operation to
* populations that contain different length arrays should throw an exception.
* Not throwing an exception should be considered a bug since it could lead to
* hard to trace bugs elsewhere.
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testDifferentLengthParents()
{
EvolutionaryOperator<int[]> crossover = new IntArrayCrossover(1, Probability.ONE);
List<int[]> population = new ArrayList<int[]>(2);
population.add(new int[]{1, 2, 3, 4, 5});
population.add(new int[]{2});
// This should cause an exception since the parents are different lengths.
crossover.apply(population, FrameworkTestUtils.getRNG());
}
}