001 /*
002 * Java Genetic Algorithm Library (jenetics-4.1.0).
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.util.RandomRegistry.getRandom;
024
025 import java.io.Serializable;
026 import java.math.BigInteger;
027 import java.util.Random;
028
029 import io.jenetics.NumericGene;
030 import io.jenetics.internal.util.Hash;
031 import io.jenetics.internal.util.require;
032 import io.jenetics.util.ISeq;
033 import io.jenetics.util.MSeq;
034 import io.jenetics.util.Mean;
035 import io.jenetics.util.RandomRegistry;
036
037 import io.jenetics.ext.internal.random;
038
039 /**
040 * Numeric chromosome implementation which holds an arbitrary sized integer
041 * number.
042 *
043 * <p>This is a <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/doc-files/ValueBased.html">
044 * value-based</a> class; use of identity-sensitive operations (including
045 * reference equality ({@code ==}), identity hash code, or synchronization) on
046 * instances of {@code IntegerGene} may have unpredictable results and should
047 * be avoided.
048 *
049 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
050 * @since 3.5
051 * @version 3.5
052 */
053 public final class BigIntegerGene
054 implements
055 NumericGene<BigInteger, BigIntegerGene>,
056 Mean<BigIntegerGene>,
057 Serializable
058 {
059 private static final long serialVersionUID = 1L;
060
061 private static final BigInteger TWO = BigInteger.valueOf(2);
062
063 private final BigInteger _value;
064 private final BigInteger _min;
065 private final BigInteger _max;
066
067 private BigIntegerGene(
068 final BigInteger value,
069 final BigInteger min,
070 final BigInteger max
071 ) {
072 _value = requireNonNull(value);
073 _min = requireNonNull(min);
074 _max = requireNonNull(max);
075 }
076
077 @Override
078 public BigInteger getAllele() {
079 return _value;
080 }
081
082 @Override
083 public BigInteger getMin() {
084 return _min;
085 }
086
087 @Override
088 public BigInteger getMax() {
089 return _max;
090 }
091
092 @Override
093 public BigIntegerGene mean(final BigIntegerGene that) {
094 final BigInteger value = _value.add(that._value).divide(TWO);
095 return of(value, _min, _max);
096 }
097
098 @Override
099 public BigIntegerGene newInstance(final Number number) {
100 return of(BigInteger.valueOf(number.longValue()), _min, _max);
101 }
102
103 @Override
104 public BigIntegerGene newInstance(final BigInteger value) {
105 return of(value, _min, _max);
106 }
107
108 @Override
109 public BigIntegerGene newInstance() {
110 return of(_min, _max);
111 }
112
113 @Override
114 public int hashCode() {
115 return Hash.of(getClass())
116 .and(_value)
117 .and(_min)
118 .and(_max).value();
119 }
120
121 @Override
122 public boolean equals(final Object obj) {
123 return obj instanceof BigIntegerGene &&
124 ((BigIntegerGene)obj)._value.equals(_value) &&
125 ((BigIntegerGene)obj)._min.equals(_min) &&
126 ((BigIntegerGene)obj)._max.equals(_max);
127 }
128
129 @Override
130 public String toString() {
131 return String.format("[%s]", _value);
132 }
133
134 /* *************************************************************************
135 * Static factory methods.
136 **************************************************************************/
137
138 static ISeq<BigIntegerGene> seq(
139 final BigInteger minimum,
140 final BigInteger maximum,
141 final int length
142 ) {
143 require.positive(length);
144
145 final Random r = getRandom();
146
147 return MSeq.<BigIntegerGene>ofLength(length)
148 .fill(() -> new BigIntegerGene(
149 random.nextBigInteger(minimum, maximum, r), minimum, maximum))
150 .toISeq();
151 }
152
153 /**
154 * Create a new random {@code BigIntegerGene} with the given value and the
155 * given range. If the {@code value} isn't within the interval [min, max],
156 * no exception is thrown. In this case the method
157 * {@link BigIntegerGene#isValid()} returns {@code false}.
158 *
159 * @param value the value of the gene.
160 * @param min the minimal valid value of this gene (inclusively).
161 * @param max the maximal valid value of this gene (inclusively).
162 * @return a new random {@code BigIntegerGene}
163 * @throws NullPointerException if one of the arguments is {@code null}
164 */
165 public static BigIntegerGene of(
166 final BigInteger value,
167 final BigInteger min,
168 final BigInteger max
169 ) {
170 return new BigIntegerGene(value, min, max);
171 }
172
173 /**
174 * Create a new random {@code BigIntegerGene}. It is guaranteed that the
175 * value of the {@code BigIntegerGene} lies in the interval [min, max].
176 *
177 * @param min the minimal valid value of this gene (inclusively).
178 * @param max the maximal valid value of this gene (inclusively).
179 * @return a new random {@code BigIntegerGene}
180 * @throws NullPointerException if one of the arguments is {@code null}
181 */
182 public static BigIntegerGene of(final BigInteger min, final BigInteger max) {
183 return of(
184 random.nextBigInteger(min, max, RandomRegistry.getRandom()),
185 min,
186 max
187 );
188 }
189
190 }
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