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.List;
021    import org.apache.commons.math.exception.util.LocalizedFormats;
022    
023    
024    /**
025     * Chromosome represented by a vector of 0s and 1s.
026     *
027     * @version $Id: BinaryChromosome.java 1139906 2011-06-26 18:42:32Z luc $
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         */
036        public BinaryChromosome(List<Integer> representation) {
037            super(representation);
038        }
039    
040        /**
041         * Constructor.
042         * @param representation array of {0,1} values representing the chromosome
043         */
044        public BinaryChromosome(Integer[] representation) {
045            super(representation);
046        }
047    
048        /**
049         * {@inheritDoc}
050         */
051        @Override
052        protected void checkValidity(List<Integer> chromosomeRepresentation)
053            throws InvalidRepresentationException {
054            for (int i : chromosomeRepresentation) {
055                if (i < 0 || i >1) {
056                    throw new InvalidRepresentationException(LocalizedFormats.INVALID_BINARY_DIGIT,
057                                                             i);
058                }
059            }
060        }
061    
062        /**
063         * Returns a representation of a random binary array of length <code>length</code>.
064         * @param length length of the array
065         * @return a random binary array of length <code>length</code>
066         */
067        public static List<Integer> randomBinaryRepresentation(int length) {
068            // random binary list
069            List<Integer> rList= new ArrayList<Integer> (length);
070            for (int j=0; j<length; j++) {
071                rList.add(GeneticAlgorithm.getRandomGenerator().nextInt(2));
072            }
073            return rList;
074        }
075    
076        /**
077         * {@inheritDoc}
078         */
079        @Override
080        protected boolean isSame(Chromosome another) {
081            // type check
082            if (! (another instanceof BinaryChromosome)) {
083                return false;
084            }
085            BinaryChromosome anotherBc = (BinaryChromosome) another;
086            // size check
087            if (getLength() != anotherBc.getLength()) {
088                return false;
089            }
090    
091            for (int i=0; i< getRepresentation().size(); i++) {
092                if (!(getRepresentation().get(i).equals(anotherBc.getRepresentation().get(i)))) {
093                    return false;
094                }
095            }
096            // all is ok
097            return true;
098        }
099    }