//=============================================================================
// 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.factories;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import org.testng.annotations.Test;
import org.uncommons.watchmaker.framework.CandidateFactory;
import org.uncommons.watchmaker.framework.FrameworkTestUtils;
/**
* Unit test for the list permutation candidate factory. Checks that it
* correctly generates populations of permutations.
* @author Daniel Dyer
*/
public class ListPermutationFactoryTest
{
private final int candidateLength = 10;
private final int populationSize = 5;
private final List<Integer> elements = new ArrayList<Integer>(candidateLength);
{
for (int i = 1; i <= candidateLength; i++)
{
elements.add(i);
}
}
/**
* Generate a completely random population. Checks to make
* sure that the correct number of candidate solutions is
* generated and that each is valid.
*/
@Test
public void testUnseededPopulation()
{
CandidateFactory<List<Integer>> factory = new ListPermutationFactory<Integer>(elements);
List<List<Integer>> population = factory.generateInitialPopulation(populationSize, FrameworkTestUtils.getRNG());
assert population.size() == populationSize : "Wrong size population generated: " + population.size();
validatePopulation(population);
}
/**
* Generate a random population with some seed candidates. Checks to make
* sure that the correct number of candidate solutions is generated and that
* each is valid.
*/
@Test
public void testSeededPopulation()
{
CandidateFactory<List<Integer>> factory = new ListPermutationFactory<Integer>(elements);
List<Integer> seed1 = new ArrayList<Integer>(elements);
List<Integer> seed2 = new ArrayList<Integer>(elements);
Collections.reverse(elements);
List<List<Integer>> seeds = new ArrayList<List<Integer>>(2);
seeds.add(seed1);
seeds.add(seed2);
List<List<Integer>> population = factory.generateInitialPopulation(populationSize,
seeds,
FrameworkTestUtils.getRNG());
// Check that the seed candidates appear in the generated population.
assert population.contains(seed1) : "Population does not contain seed candidate 1.";
assert population.contains(seed2) : "Population does not contain seed candidate 2.";
validatePopulation(population);
}
/**
* It is an error if the number of seed candidates is greater than the
* population size. In this case an exception should be thrown. Not
* throwing an exception is wrong because it would permit undetected bugs
* in programs that use the factory.
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testTooManySeedCandidates()
{
CandidateFactory<List<Integer>> factory = new ListPermutationFactory<Integer>(elements);
List<List<Integer>> seeds = new LinkedList<List<Integer>>();
seeds.add(elements);
seeds.add(elements);
seeds.add(elements);
// The following call should cause an exception since the 3 seed candidates
// won't fit into a population of size 2.
factory.generateInitialPopulation(2, seeds, FrameworkTestUtils.getRNG());
}
/**
* Make sure each candidate is valid (contains each element exactly once).
* @param population The population to be validated.
*/
private void validatePopulation(List<List<Integer>> population)
{
assert population.size() == populationSize : "Wrong size population generated: " + population.size();
for (List<Integer> candidate : population)
{
assert candidate.size() == candidateLength : "Wrong size candidate generated: " + candidate.size();
for (int i = 1; i < candidateLength; i++)
{
assert candidate.contains(i) : "Candidate is missing element " + i + ".";
}
}
}
}