001 /*
002 * Java Genetic Algorithm Library (jenetics-4.3.0).
003 * Copyright (c) 2007-2018 Franz Wilhelmstötter
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * 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 * Author:
018 * Franz Wilhelmstötter (franz.wilhelmstoetter@gmail.com)
019 */
020 package io.jenetics.ext;
021
022 import static java.util.Objects.requireNonNull;
023 import static io.jenetics.internal.util.Hashes.hash;
024 import static io.jenetics.util.RandomRegistry.getRandom;
025
026 import java.io.Serializable;
027 import java.math.BigInteger;
028 import java.util.Objects;
029 import java.util.Random;
030
031 import io.jenetics.NumericGene;
032 import io.jenetics.internal.util.require;
033 import io.jenetics.util.ISeq;
034 import io.jenetics.util.MSeq;
035 import io.jenetics.util.Mean;
036 import io.jenetics.util.RandomRegistry;
037
038 import io.jenetics.ext.internal.random;
039
040 /**
041 * Numeric chromosome implementation which holds an arbitrary sized integer
042 * number.
043 *
044 * <p>This is a <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/doc-files/ValueBased.html">
045 * value-based</a> class; use of identity-sensitive operations (including
046 * reference equality ({@code ==}), identity hash code, or synchronization) on
047 * instances of {@code IntegerGene} may have unpredictable results and should
048 * be avoided.
049 *
050 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
051 * @since 3.5
052 * @version 3.5
053 */
054 public final class BigIntegerGene
055 implements
056 NumericGene<BigInteger, BigIntegerGene>,
057 Mean<BigIntegerGene>,
058 Serializable
059 {
060 private static final long serialVersionUID = 1L;
061
062 private static final BigInteger TWO = BigInteger.valueOf(2);
063
064 private final BigInteger _value;
065 private final BigInteger _min;
066 private final BigInteger _max;
067
068 private BigIntegerGene(
069 final BigInteger value,
070 final BigInteger min,
071 final BigInteger max
072 ) {
073 _value = requireNonNull(value);
074 _min = requireNonNull(min);
075 _max = requireNonNull(max);
076 }
077
078 @Override
079 public BigInteger getAllele() {
080 return _value;
081 }
082
083 @Override
084 public BigInteger getMin() {
085 return _min;
086 }
087
088 @Override
089 public BigInteger getMax() {
090 return _max;
091 }
092
093 @Override
094 public BigIntegerGene mean(final BigIntegerGene that) {
095 final BigInteger value = _value.add(that._value).divide(TWO);
096 return of(value, _min, _max);
097 }
098
099 @Override
100 public BigIntegerGene newInstance(final Number number) {
101 return of(BigInteger.valueOf(number.longValue()), _min, _max);
102 }
103
104 @Override
105 public BigIntegerGene newInstance(final BigInteger value) {
106 return of(value, _min, _max);
107 }
108
109 @Override
110 public BigIntegerGene newInstance() {
111 return of(_min, _max);
112 }
113
114 @Override
115 public int hashCode() {
116 return hash(_value, hash(_min, hash(_max, hash(getClass()))));
117 }
118
119 @Override
120 public boolean equals(final Object obj) {
121 return obj == this ||
122 obj instanceof BigIntegerGene &&
123 Objects.equals(((BigIntegerGene)obj)._value, _value) &&
124 Objects.equals(((BigIntegerGene)obj)._min, _min) &&
125 Objects.equals(((BigIntegerGene)obj)._max, _max);
126 }
127
128 @Override
129 public String toString() {
130 return String.format("[%s]", _value);
131 }
132
133 /* *************************************************************************
134 * Static factory methods.
135 **************************************************************************/
136
137 static ISeq<BigIntegerGene> seq(
138 final BigInteger minimum,
139 final BigInteger maximum,
140 final int length
141 ) {
142 require.positive(length);
143
144 final Random r = getRandom();
145
146 return MSeq.<BigIntegerGene>ofLength(length)
147 .fill(() -> new BigIntegerGene(
148 random.nextBigInteger(minimum, maximum, r), minimum, maximum))
149 .toISeq();
150 }
151
152 /**
153 * Create a new random {@code BigIntegerGene} with the given value and the
154 * given range. If the {@code value} isn't within the interval [min, max],
155 * no exception is thrown. In this case the method
156 * {@link BigIntegerGene#isValid()} returns {@code false}.
157 *
158 * @param value the value of the gene.
159 * @param min the minimal valid value of this gene (inclusively).
160 * @param max the maximal valid value of this gene (inclusively).
161 * @return a new random {@code BigIntegerGene}
162 * @throws NullPointerException if one of the arguments is {@code null}
163 */
164 public static BigIntegerGene of(
165 final BigInteger value,
166 final BigInteger min,
167 final BigInteger max
168 ) {
169 return new BigIntegerGene(value, min, max);
170 }
171
172 /**
173 * Create a new random {@code BigIntegerGene}. It is guaranteed that the
174 * value of the {@code BigIntegerGene} lies in the interval [min, max].
175 *
176 * @param min the minimal valid value of this gene (inclusively).
177 * @param max the maximal valid value of this gene (inclusively).
178 * @return a new random {@code BigIntegerGene}
179 * @throws NullPointerException if one of the arguments is {@code null}
180 */
181 public static BigIntegerGene of(final BigInteger min, final BigInteger max) {
182 return of(
183 random.nextBigInteger(min, max, RandomRegistry.getRandom()),
184 min,
185 max
186 );
187 }
188
189 }
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