//=============================================================================
// 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.examples.monalisa;
import java.awt.Dimension;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.testng.annotations.Test;
import org.uncommons.maths.random.Probability;
import org.uncommons.watchmaker.examples.ExamplesTestUtils;
import org.uncommons.watchmaker.framework.EvolutionaryOperator;
/**
* Unit test for the {@link AddPolygonMutation} evolutionary operator.
* @author Daniel Dyer
*/
public class AddPolygonMutationTest
{
private final PolygonImageFactory factory = new PolygonImageFactory(new Dimension(200, 200));
@Test
public void testAddPolygon()
{
List<ColouredPolygon> image = factory.generateRandomCandidate(ExamplesTestUtils.getRNG());
assert image.size() == 2 : "Image should have 2 polygons";
List<List<ColouredPolygon>> list = new ArrayList<List<ColouredPolygon>>(1);
list.add(image);
EvolutionaryOperator<List<ColouredPolygon>> mutation = new AddPolygonMutation(Probability.ONE,
factory,
5);
List<List<ColouredPolygon>> evolved = mutation.apply(list, ExamplesTestUtils.getRNG());
assert evolved.size() == 1 : "Population size should not be altered by mutation.";
assert evolved.get(0).size() == image.size() + 1 : "Image should have 1 extra polygon after mutation.";
}
@Test
public void testZeroProbability()
{
List<ColouredPolygon> image = factory.generateRandomCandidate(ExamplesTestUtils.getRNG());
assert image.size() == 2 : "Image should have 2 polygons";
List<List<ColouredPolygon>> list = new ArrayList<List<ColouredPolygon>>(1);
list.add(image);
EvolutionaryOperator<List<ColouredPolygon>> mutation = new AddPolygonMutation(Probability.ZERO,
factory,
5);
List<List<ColouredPolygon>> evolved = mutation.apply(list, ExamplesTestUtils.getRNG());
assert evolved.size() == 1 : "Population size should not be altered by mutation.";
assert evolved.get(0).size() == image.size() : "Image should have same number of polygons.";
assert evolved.get(0) == image : "Image should not have been changed at all.";
}
/**
* If the image already has the maximum permitted number of polygons, extra polygons
* should not be added by mutation.
*/
@Test
public void testAddMaxPolygons()
{
List<ColouredPolygon> image = Arrays.asList(factory.createRandomPolygon(ExamplesTestUtils.getRNG()),
factory.createRandomPolygon(ExamplesTestUtils.getRNG()),
factory.createRandomPolygon(ExamplesTestUtils.getRNG()));
List<List<ColouredPolygon>> list = new ArrayList<List<ColouredPolygon>>(1);
list.add(image);
EvolutionaryOperator<List<ColouredPolygon>> mutation = new AddPolygonMutation(Probability.ONE,
factory,
3);
List<List<ColouredPolygon>> evolved = mutation.apply(list, ExamplesTestUtils.getRNG());
assert evolved.size() == 1 : "Population size should not be altered by mutation.";
assert evolved.get(0).size() == image.size() : "Image should have no more than the maximum number of polygons.";
assert evolved.get(0) == image : "Image should not have been changed at all.";
}
/**
* An image must have at least 2 polygons. The configured maximum must respect this.
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testInvalidMaximum()
{
new AddPolygonMutation(Probability.ONE, factory, 1); // Invalid, should throw IllegalArgumentException.
}
}