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 * https://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
18 /*
19 * This is not the original file distributed by the Apache Software Foundation
20 * It has been modified by the Hipparchus project
21 */
22
23 package org.hipparchus.random;
24
25 import org.hipparchus.util.FastMath;
26
27 /**
28 * This class implements a normalized uniform random generator.
29 * <p>
30 * Since it is a normalized random generator, it generates values
31 * from a uniform distribution with mean equal to 0 and standard
32 * deviation equal to 1. Generated values fall in the range
33 * [-√3, +√3].
34 */
35 public class UniformRandomGenerator implements NormalizedRandomGenerator {
36
37 /** Square root of three. */
38 private static final double SQRT3 = FastMath.sqrt(3.0);
39
40 /** Underlying generator. */
41 private final RandomGenerator generator;
42
43 /** Create a new generator.
44 * @param generator underlying random generator to use
45 */
46 public UniformRandomGenerator(RandomGenerator generator) {
47 this.generator = generator;
48 }
49
50 /**
51 * Generate a random scalar with null mean and unit standard deviation.
52 * <p>
53 * The number generated is uniformly distributed between \(-\sqrt{3}\)
54 * and \(+\sqrt{3}\).
55 *
56 * @return a random scalar with null mean and unit standard deviation
57 */
58 @Override
59 public double nextNormalizedDouble() {
60 return SQRT3 * (2 * generator.nextDouble() - 1.0);
61 }
62
63 }