    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
    022
    023    /**
    024     * Chromosome represented by a vector of 0s and 1s.
    025     *
    026     * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $
    027     * @since 2.0
    028     */
    029    public abstract class BinaryChromosome extends AbstractListChromosome<Integer> {
    030
    031        /**
    032         * Constructor.
    033         * @param representation list of {0,1} values representing the chromosome
    034         */
    035        public BinaryChromosome(List<Integer> representation) {
    036            super(representation);
    037        }
    038
    039        /**
    040         * Constructor.
    041         * @param representation array of {0,1} values representing the chromosome
    042         */
    043        public BinaryChromosome(Integer[] representation) {
    044            super(representation);
    045        }
    046
    047        /**
    048         * {@inheritDoc}
    049         */
    050        @Override
    051        protected void checkValidity(List<Integer> chromosomeRepresentation) throws InvalidRepresentationException {
    052            for (int i : chromosomeRepresentation) {
    053                if (i < 0 || i >1)
    054                    throw new InvalidRepresentationException("Elements can be only 0 or 1.");
    055            }
    056        }
    057
    058        /**
    059         * Returns a representation of a random binary array of length <code>length</code>.
    060         * @param length length of the array
    061         * @return a random binary array of length <code>length</code>
    062         */
    063        public static List<Integer> randomBinaryRepresentation(int length) {
    064            // random binary list
    065            List<Integer> rList= new ArrayList<Integer> (length);
    066            for (int j=0; j<length; j++) {
    067                rList.add(GeneticAlgorithm.getRandomGenerator().nextInt(2));
    068            }
    069            return rList;
    070        }
    071
    072        /**
    073         * {@inheritDoc}
    074         */
    075        @Override
    076        protected boolean isSame(Chromosome another) {
    077            // type check
    078            if (! (another instanceof BinaryChromosome))
    079                return false;
    080            BinaryChromosome anotherBc = (BinaryChromosome) another;
    081            // size check
    082            if (getLength() != anotherBc.getLength())
    083                return false;
    084
    085            for (int i=0; i< getRepresentation().size(); i++) {
    086                if (!(getRepresentation().get(i).equals(anotherBc.getRepresentation().get(i))))
    087                    return false;
    088            }
    089            // all is ok
    090            return true;
    091        }
    092    }