1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.math.genetics;
18  
19  import static org.junit.Assert.*;
20  
21  import org.junit.Test;
22  
23  public class ElitisticListPopulationTest {
24      
25      private static int counter = 0;
26  
27      @Test
28      public void testNextGeneration() {
29          ElitisticListPopulation pop = new ElitisticListPopulation(100, 0.203);
30          
31          for (int i=0; i<pop.getPopulationLimit(); i++) {
32              pop.addChromosome(new DummyChromosome());
33          }
34          
35          Population nextGeneration = pop.nextGeneration();
36          
37          assertEquals(20, nextGeneration.getPopulationSize());
38      }
39      
40      private static class DummyChromosome extends Chromosome {
41          private final int fitness;
42          
43          public DummyChromosome() {
44              this.fitness = counter;
45              counter++;
46          }
47          
48          public double fitness() {            
49              return this.fitness;
50          }
51      }
52  
53  }