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.Arrays;
021 import java.util.Collections;
022 import java.util.List;
023
024 /**
025 * Chromosome represented by an immutable list of a fixed length.
026 *
027 * @param <T> type of the representation list
028 * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $
029 * @since 2.0
030 */
031 public abstract class AbstractListChromosome<T> extends Chromosome {
032
033 /** List representing the chromosome */
034 private final List<T> representation;
035
036 /**
037 * Constructor.
038 * @param representation inner representation of the chromosome
039 */
040 public AbstractListChromosome(final List<T> representation) {
041 try {
042 checkValidity(representation);
043 } catch (InvalidRepresentationException e) {
044 throw new IllegalArgumentException(String.format("Invalid representation for %s", getClass().getSimpleName()), e);
045 }
046 this.representation = Collections.unmodifiableList(new ArrayList<T> (representation));
047 }
048
049 /**
050 * Constructor.
051 * @param representation inner representation of the chromosome
052 */
053 public AbstractListChromosome(final T[] representation) {
054 this(Arrays.asList(representation));
055 }
056
057 /**
058 *
059 * Asserts that <code>representation</code> can represent a valid chromosome.
060 * @param chromosomeRepresentation representation of the chromosome
061 * @throws InvalidRepresentationException iff the <code>representation</code> can not represent
062 * a valid chromosome
063 */
064 protected abstract void checkValidity(List<T> chromosomeRepresentation) throws InvalidRepresentationException;
065
066 /**
067 * Returns the (immutable) inner representation of the chromosome.
068 * @return the representation of the chromosome
069 */
070 protected List<T> getRepresentation() {
071 return representation;
072 }
073
074 /**
075 * Returns the length of the chromosome.
076 * @return the length of the chromosome
077 */
078 public int getLength() {
079 return getRepresentation().size();
080 }
081
082 /**
083 * Creates a new instance of the same class as <code>this</code> is, with a
084 * given <code>arrayRepresentation</code>. This is needed in crossover and
085 * mutation operators, where we need a new instance of the same class, but
086 * with different array representation.
087 *
088 * Usually, this method just calls a constructor of the class.
089 *
090 * @param chromosomeRepresentation
091 * the inner array representation of the new chromosome.
092 * @return new instance extended from FixedLengthChromosome with the given
093 * arrayRepresentation
094 */
095 public abstract AbstractListChromosome<T> newFixedLengthChromosome(final List<T> chromosomeRepresentation);
096
097 /**
098 * {@inheritDoc}
099 */
100 @Override
101 public String toString() {
102 return String.format("(f=%s %s)", getFitness(), getRepresentation());
103 }
104 }