001 /*
002 * Java Genetic Algorithm Library (jenetics-3.0.0).
003 * Copyright (c) 2007-2014 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@gmx.at)
019 */
020 package org.jenetics.util;
021
022 import java.util.Random;
023
024 import org.jenetics.internal.math.random;
025
026 /**
027 * Abstract {@code Random} class with additional <i>next</i> random number
028 * methods.
029 *
030 * @author <a href="mailto:franz.wilhelmstoetter@gmx.at">Franz Wilhelmstötter</a>
031 * @since 1.2
032 * @version 2.0 — <em>$Date: 2014-12-28 $</em>
033 */
034 abstract class PRNG extends Random {
035
036 private static final long serialVersionUID = 1L;
037
038 /**
039 * Create a new {@code PRNG} instance with the given {@code seed}.
040 *
041 * @param seed the seed of the new {@code PRNG} instance.
042 */
043 protected PRNG(final long seed) {
044 super(seed);
045 }
046
047 /**
048 * Create a new {@code PRNG} instance with a seed created with the
049 * {@link org.jenetics.internal.math.random#seed()} value.
050 */
051 protected PRNG() {
052 this(random.seed());
053 }
054
055 /**
056 * Returns a pseudorandom, uniformly distributed int value between min and
057 * max (end points included).
058 *
059 * @param min lower bound for generated integer (inclusively)
060 * @param max upper bound for generated integer (inclusively)
061 * @return a random integer greater than or equal to {@code min} and less
062 * than or equal to {@code max}
063 * @throws IllegalArgumentException if {@code min >= max}
064 *
065 * @see org.jenetics.internal.math.random#nextInt(java.util.Random, int, int)
066 */
067 public int nextInt(final int min, final int max) {
068 return random.nextInt(this, min, max);
069 }
070
071 /**
072 * Returns a pseudorandom, uniformly distributed int value between min
073 * and max (end points included).
074 *
075 * @param min lower bound for generated long integer (inclusively)
076 * @param max upper bound for generated long integer (inclusively)
077 * @return a random long integer greater than or equal to {@code min}
078 * and less than or equal to {@code max}
079 * @throws IllegalArgumentException if {@code min >= max}
080 *
081 * @see org.jenetics.internal.math.random#nextLong(java.util.Random, long, long)
082 */
083 public long nextLong(final long min, final long max) {
084 return random.nextLong(this, min, max);
085 }
086
087 /**
088 * Returns a pseudorandom, uniformly distributed int value between 0
089 * (inclusive) and the specified value (exclusive), drawn from the given
090 * random number generator's sequence.
091 *
092 * @param n the bound on the random number to be returned. Must be
093 * positive.
094 * @return the next pseudorandom, uniformly distributed int value
095 * between 0 (inclusive) and n (exclusive) from the given random
096 * number generator's sequence
097 * @throws IllegalArgumentException if n is smaller than 1.
098 *
099 * @see org.jenetics.internal.math.random#nextLong(java.util.Random, long)
100 */
101 public long nextLong(final long n) {
102 return random.nextLong(this, n);
103 }
104
105 /**
106 * Returns a pseudorandom, uniformly distributed double value between
107 * min (inclusively) and max (exclusively).
108 *
109 * @param min lower bound for generated float value (inclusively)
110 * @param max upper bound for generated float value (exclusively)
111 * @return a random float greater than or equal to {@code min} and less
112 * than to {@code max}
113 *
114 * @see org.jenetics.internal.math.random#nextFloat(java.util.Random, float, float)
115 */
116 public float nextFloat(final float min, final float max) {
117 return random.nextFloat(this, min, max);
118 }
119
120 /**
121 * Returns a pseudorandom, uniformly distributed double value between
122 * min (inclusively) and max (exclusively).
123 *
124 * @param min lower bound for generated double value (inclusively)
125 * @param max upper bound for generated double value (exclusively)
126 * @return a random double greater than or equal to {@code min} and less
127 * than to {@code max}
128 *
129 * @see org.jenetics.internal.math.random#nextDouble(java.util.Random, double, double)
130 */
131 public double nextDouble(final double min, final double max) {
132 return random.nextDouble(this, min, max);
133 }
134
135 }
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