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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    *      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  package org.hipparchus.analysis.solvers;
23  
24  import org.hipparchus.analysis.QuinticFunction;
25  import org.hipparchus.analysis.differentiation.UnivariateDifferentiableFunction;
26  import org.hipparchus.analysis.function.Sin;
27  import org.hipparchus.util.FastMath;
28  import org.junit.Assert;
29  import org.junit.Test;
30  
31  
32  /**
33   */
34  public final class NewtonRaphsonSolverTest {
35      /**
36       *
37       */
38      @Test
39      public void testSinZero() {
40          UnivariateDifferentiableFunction f = new Sin();
41          double result;
42  
43          NewtonRaphsonSolver solver = new NewtonRaphsonSolver();
44          result = solver.solve(100, f, 3, 4);
45          Assert.assertEquals(result, FastMath.PI, solver.getAbsoluteAccuracy());
46  
47          result = solver.solve(100, f, 1, 4);
48          Assert.assertEquals(result, FastMath.PI, solver.getAbsoluteAccuracy());
49  
50          Assert.assertTrue(solver.getEvaluations() > 0);
51      }
52  
53      /**
54       *
55       */
56      @Test
57      public void testQuinticZero() {
58          final UnivariateDifferentiableFunction f = new QuinticFunction();
59          double result;
60  
61          NewtonRaphsonSolver solver = new NewtonRaphsonSolver();
62          result = solver.solve(100, f, -0.2, 0.2);
63          Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
64  
65          result = solver.solve(100, f, -0.1, 0.3);
66          Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
67  
68          result = solver.solve(100, f, -0.3, 0.45);
69          Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
70  
71          result = solver.solve(100, f, 0.3, 0.7);
72          Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
73  
74          result = solver.solve(100, f, 0.2, 0.6);
75          Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
76  
77          result = solver.solve(100, f, 0.05, 0.95);
78          Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
79  
80          result = solver.solve(100, f, 0.85, 1.25);
81          Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
82  
83          result = solver.solve(100, f, 0.8, 1.2);
84          Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
85  
86          result = solver.solve(100, f, 0.85, 1.75);
87          Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
88  
89          result = solver.solve(100, f, 0.55, 1.45);
90          Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
91  
92          result = solver.solve(100, f, 0.85, 5);
93          Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
94      }
95  }