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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.RestorableUniformRandomProvider;
20  import org.apache.commons.rng.simple.RandomSource;
21  import org.junit.Test;
22  
23  /**
24   * Test for the {@link BoxMullerLogNormalSampler}. The tests hit edge cases for the sampler.
25   */
26  public class BoxMullerLogNormalSamplerTest {
27      /**
28       * Test the constructor with a bad scale.
29       */
30      @Test(expected = IllegalArgumentException.class)
31      public void testConstructorThrowsWithNegativeScale() {
32          final RestorableUniformRandomProvider rng =
33              RandomSource.create(RandomSource.SPLIT_MIX_64);
34          final double scale = -1e-6;
35          final double shape = 1;
36          @SuppressWarnings("unused")
37          final BoxMullerLogNormalSampler sampler =
38              new BoxMullerLogNormalSampler(rng, scale, shape);
39      }
40  
41      /**
42       * Test the constructor with a bad shape.
43       */
44      @Test(expected = IllegalArgumentException.class)
45      public void testConstructorThrowsWithZeroShape() {
46          final RestorableUniformRandomProvider rng =
47              RandomSource.create(RandomSource.SPLIT_MIX_64);
48          final double scale = 1;
49          final double shape = 0;
50          @SuppressWarnings("unused")
51          final BoxMullerLogNormalSampler sampler =
52              new BoxMullerLogNormalSampler(rng, scale, shape);
53      }
54  }