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.rng.sampling.distribution;
18
19 import org.apache.commons.rng.UniformRandomProvider;
20
21 /**
22 * Sampling from a <a href="https://en.wikipedia.org/wiki/Log-normal_distribution">
23 * log-normal distribution</a>.
24 * Uses {@link BoxMullerNormalizedGaussianSampler} as the underlying sampler.
25 *
26 * <p>Sampling uses:</p>
27 *
28 * <ul>
29 * <li>{@link UniformRandomProvider#nextDouble()}
30 * <li>{@link UniformRandomProvider#nextLong()}
31 * </ul>
32 *
33 * @since 1.0
34 *
35 * @deprecated Since version 1.1. Please use {@link LogNormalSampler} instead.
36 */
37 @Deprecated
38 public class BoxMullerLogNormalSampler
39 extends SamplerBase
40 implements ContinuousSampler {
41 /** Delegate. */
42 private final ContinuousSampler sampler;
43
44 /**
45 * Create an instance.
46 *
47 * @param rng Generator of uniformly distributed random numbers.
48 * @param mu Mean of the natural logarithm of the distribution values.
49 * @param sigma Standard deviation of the natural logarithm of the distribution values.
50 * @throws IllegalArgumentException if {@code sigma <= 0}.
51 */
52 public BoxMullerLogNormalSampler(UniformRandomProvider rng,
53 double mu,
54 double sigma) {
55 super(null);
56 sampler = LogNormalSampler.of(new BoxMullerNormalizedGaussianSampler(rng),
57 mu, sigma);
58 }
59
60 /** {@inheritDoc} */
61 @Override
62 public double sample() {
63 return sampler.sample();
64 }
65
66 /** {@inheritDoc} */
67 @Override
68 public String toString() {
69 return sampler.toString();
70 }
71 }