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.math3.genetics;
018    
019    import java.util.ArrayList;
020    import java.util.List;
021    import org.apache.commons.math3.exception.util.LocalizedFormats;
022    
023    
024    /**
025     * Chromosome represented by a vector of 0s and 1s.
026     *
027     * @version $Id: BinaryChromosome.java 1416643 2012-12-03 19:37:14Z tn $
028     * @since 2.0
029     */
030    public abstract class BinaryChromosome extends AbstractListChromosome<Integer> {
031    
032        /**
033         * Constructor.
034         * @param representation list of {0,1} values representing the chromosome
035         * @throws InvalidRepresentationException iff the <code>representation</code> can not represent a valid chromosome
036         */
037        public BinaryChromosome(List<Integer> representation) throws InvalidRepresentationException {
038            super(representation);
039        }
040    
041        /**
042         * Constructor.
043         * @param representation array of {0,1} values representing the chromosome
044         * @throws InvalidRepresentationException iff the <code>representation</code> can not represent a valid chromosome
045         */
046        public BinaryChromosome(Integer[] representation) throws InvalidRepresentationException {
047            super(representation);
048        }
049    
050        /**
051         * {@inheritDoc}
052         */
053        @Override
054        protected void checkValidity(List<Integer> chromosomeRepresentation) throws InvalidRepresentationException {
055            for (int i : chromosomeRepresentation) {
056                if (i < 0 || i >1) {
057                    throw new InvalidRepresentationException(LocalizedFormats.INVALID_BINARY_DIGIT,
058                                                             i);
059                }
060            }
061        }
062    
063        /**
064         * Returns a representation of a random binary array of length <code>length</code>.
065         * @param length length of the array
066         * @return a random binary array of length <code>length</code>
067         */
068        public static List<Integer> randomBinaryRepresentation(int length) {
069            // random binary list
070            List<Integer> rList= new ArrayList<Integer> (length);
071            for (int j=0; j<length; j++) {
072                rList.add(GeneticAlgorithm.getRandomGenerator().nextInt(2));
073            }
074            return rList;
075        }
076    
077        @Override
078        protected boolean isSame(Chromosome another) {
079            // type check
080            if (! (another instanceof BinaryChromosome)) {
081                return false;
082            }
083            BinaryChromosome anotherBc = (BinaryChromosome) another;
084            // size check
085            if (getLength() != anotherBc.getLength()) {
086                return false;
087            }
088    
089            for (int i=0; i< getRepresentation().size(); i++) {
090                if (!(getRepresentation().get(i).equals(anotherBc.getRepresentation().get(i)))) {
091                    return false;
092                }
093            }
094            // all is ok
095            return true;
096        }
097    }