1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.math.genetics;
18
19 import java.util.ArrayList;
20 import java.util.Arrays;
21 import java.util.Collections;
22 import java.util.List;
23
24 /**
25 * Chromosome represented by an immutable list of a fixed length.
26 *
27 * @param <T> type of the representation list
28 * @version $Revision: 799857 $ $Date: 2009-08-01 09:07:12 -0400 (Sat, 01 Aug 2009) $
29 * @since 2.0
30 */
31 public abstract class AbstractListChromosome<T> extends Chromosome {
32
33 /** List representing the chromosome */
34 private final List<T> representation;
35
36 /**
37 * Constructor.
38 * @param representation inner representation of the chromosome
39 */
40 public AbstractListChromosome(final List<T> representation) {
41 try {
42 checkValidity(representation);
43 } catch (InvalidRepresentationException e) {
44 throw new IllegalArgumentException(String.format("Invalid representation for %s", getClass().getSimpleName()), e);
45 }
46 this.representation = Collections.unmodifiableList(new ArrayList<T> (representation));
47 }
48
49 /**
50 * Constructor.
51 * @param representation inner representation of the chromosome
52 */
53 public AbstractListChromosome(final T[] representation) {
54 this(Arrays.asList(representation));
55 }
56
57 /**
58 *
59 * Asserts that <code>representation</code> can represent a valid chromosome.
60 * @param representation representation of the chromosome
61 * @throws InvalidRepresentationException iff the <code>representation</code> can not represent
62 * a valid chromosome
63 */
64 protected abstract void checkValidity(List<T> representation) throws InvalidRepresentationException;
65
66 /**
67 * Returns the (immutable) inner representation of the chromosome.
68 * @return the representation of the chromosome
69 */
70 protected List<T> getRepresentation() {
71 return representation;
72 }
73
74 /**
75 * Returns the length of the chromosome.
76 * @return the length of the chromosome
77 */
78 public int getLength() {
79 return getRepresentation().size();
80 }
81
82 /**
83 * Creates a new instance of the same class as <code>this</code> is, with a
84 * given <code>arrayRepresentation</code>. This is needed in crossover and
85 * mutation operators, where we need a new instance of the same class, but
86 * with different array representation.
87 *
88 * Usually, this method just calls a constructor of the class.
89 *
90 * @param representation
91 * the inner array representation of the new chromosome.
92 * @return new instance extended from FixedLengthChromosome with the given
93 * arrayRepresentation
94 */
95 public abstract AbstractListChromosome<T> newFixedLengthChromosome(final List<T> representation);
96
97 /**
98 * {@inheritDoc}
99 */
100 @Override
101 public String toString() {
102 return String.format("(f=%s %s)", getFitness(), getRepresentation());
103 }
104 }