1dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond/* 2dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * Licensed to the Apache Software Foundation (ASF) under one or more 3dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * contributor license agreements. See the NOTICE file distributed with 4dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * this work for additional information regarding copyright ownership. 5dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * The ASF licenses this file to You under the Apache License, Version 2.0 6dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * (the "License"); you may not use this file except in compliance with 7dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * the License. You may obtain a copy of the License at 8dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * 9dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * http://www.apache.org/licenses/LICENSE-2.0 10dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * 11dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * Unless required by applicable law or agreed to in writing, software 12dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * distributed under the License is distributed on an "AS IS" BASIS, 13dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * See the License for the specific language governing permissions and 15dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * limitations under the License. 16dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond */ 17dee0849a9704d532af0b550146cbafbaa6ee1d19Raymondpackage org.apache.commons.math.genetics; 18dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 19dee0849a9704d532af0b550146cbafbaa6ee1d19Raymondimport java.util.ArrayList; 20dee0849a9704d532af0b550146cbafbaa6ee1d19Raymondimport java.util.List; 21dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 22dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond/** 23dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * Mutation for {@link BinaryChromosome}s. Randomly changes one gene. 24dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * 25dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $ 26dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @since 2.0 27dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond */ 28dee0849a9704d532af0b550146cbafbaa6ee1d19Raymondpublic class BinaryMutation implements MutationPolicy { 29dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 30dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond /** 31dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * Mutate the given chromosome. Randomly changes one gene. 32dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @param original the original chromosome. 33dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond * @return the mutated chromomsome. 34dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond */ 35dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond public Chromosome mutate(Chromosome original) { 36dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond if (!(original instanceof BinaryChromosome)) { 37dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond throw new IllegalArgumentException("Binary mutation works on BinaryChromosome only."); 38dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond } 39dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 40dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond BinaryChromosome origChrom = (BinaryChromosome) original; 41dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond List<Integer> newRepr = new ArrayList<Integer>(origChrom.getRepresentation()); 42dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 43dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond // randomly select a gene 44dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond int geneIndex = GeneticAlgorithm.getRandomGenerator().nextInt(origChrom.getLength()); 45dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond // and change it 46dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond newRepr.set(geneIndex, origChrom.getRepresentation().get(geneIndex) == 0 ? 1 : 0); 47dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 48dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond Chromosome newChrom = origChrom.newFixedLengthChromosome(newRepr); 49dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond return newChrom; 50dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond } 51dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond 52dee0849a9704d532af0b550146cbafbaa6ee1d19Raymond} 53