001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.math.genetics; 018 019 import java.util.ArrayList; 020 import java.util.Iterator; 021 import java.util.List; 022 023 /** 024 * Population of chromosomes represented by a {@link List}. 025 * 026 * @since 2.0 027 * @version $Revision: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $ 028 */ 029 public abstract class ListPopulation implements Population { 030 031 /** List of chromosomes */ 032 private List<Chromosome> chromosomes; 033 034 /** maximial size of the population */ 035 private int populationLimit; 036 037 038 /** 039 * Creates a new ListPopulation instance. 040 * 041 * @param chromosomes list of chromosomes in the population 042 * @param populationLimit maximal size of the population 043 */ 044 public ListPopulation (List<Chromosome> chromosomes, int populationLimit) { 045 if (chromosomes.size() > populationLimit) { 046 throw new IllegalArgumentException("List of chromosomes bigger than maxPopulationSize."); 047 } 048 if (populationLimit < 0) { 049 throw new IllegalArgumentException("Population limit has to be >= 0"); 050 } 051 052 this.chromosomes = chromosomes; 053 this.populationLimit = populationLimit; 054 } 055 056 /** 057 * Creates a new ListPopulation instance and initializes its inner 058 * chromosome list. 059 * 060 * @param populationLimit maximal size of the population 061 */ 062 public ListPopulation (int populationLimit) { 063 if (populationLimit < 0) { 064 throw new IllegalArgumentException("Population limit has to be >= 0"); 065 } 066 this.populationLimit = populationLimit; 067 this.chromosomes = new ArrayList<Chromosome>(populationLimit); 068 } 069 070 /** 071 * Sets the list of chromosomes. 072 * @param chromosomes the list of chromosomes 073 */ 074 public void setChromosomes(List<Chromosome> chromosomes) { 075 this.chromosomes = chromosomes; 076 } 077 078 /** 079 * Access the list of chromosomes. 080 * @return the list of chromosomes 081 */ 082 public List<Chromosome> getChromosomes() { 083 return chromosomes; 084 } 085 086 /** 087 * Add the given chromosome to the population. 088 * @param chromosome the chromosome to add. 089 */ 090 public void addChromosome(Chromosome chromosome) { 091 this.chromosomes.add(chromosome); 092 } 093 094 /** 095 * Access the fittest chromosome in this population. 096 * @return the fittest chromosome. 097 */ 098 public Chromosome getFittestChromosome() { 099 // best so far 100 Chromosome bestChromosome = this.chromosomes.get(0); 101 for (Chromosome chromosome : this.chromosomes) { 102 if (chromosome.compareTo(bestChromosome) > 0) { 103 // better chromosome found 104 bestChromosome = chromosome; 105 } 106 } 107 return bestChromosome; 108 } 109 110 /** 111 * Access the maximum population size. 112 * @return the maximum population size. 113 */ 114 public int getPopulationLimit() { 115 return this.populationLimit; 116 } 117 118 /** 119 * Sets the maximal population size. 120 * @param populationLimit maximal population size. 121 */ 122 public void setPopulationLimit(int populationLimit) { 123 this.populationLimit = populationLimit; 124 } 125 126 /** 127 * Access the current population size. 128 * @return the current population size. 129 */ 130 public int getPopulationSize() { 131 return this.chromosomes.size(); 132 } 133 134 /** 135 * {@inheritDoc} 136 */ 137 @Override 138 public String toString() { 139 return this.chromosomes.toString(); 140 } 141 142 /** 143 * Chromosome list iterator 144 * 145 * @return chromosome iterator 146 */ 147 public Iterator<Chromosome> iterator() { 148 return chromosomes.iterator(); 149 } 150 }