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17 package org.apache.commons.math4.legacy.analysis.solvers;
18
19 import org.apache.commons.math4.legacy.analysis.QuinticFunction;
20 import org.apache.commons.math4.legacy.analysis.differentiation.UnivariateDifferentiableFunction;
21 import org.apache.commons.math4.legacy.analysis.function.Sin;
22 import org.apache.commons.math4.core.jdkmath.JdkMath;
23 import org.junit.Assert;
24 import org.junit.Test;
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29 public final class NewtonRaphsonSolverTest {
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33 @Test
34 public void testSinZero() {
35 UnivariateDifferentiableFunction f = new Sin();
36 double result;
37
38 NewtonRaphsonSolver solver = new NewtonRaphsonSolver();
39 result = solver.solve(100, f, 3, 4);
40 Assert.assertEquals(result, JdkMath.PI, solver.getAbsoluteAccuracy());
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42 result = solver.solve(100, f, 1, 4);
43 Assert.assertEquals(result, JdkMath.PI, solver.getAbsoluteAccuracy());
44
45 Assert.assertTrue(solver.getEvaluations() > 0);
46 }
47
48
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50
51 @Test
52 public void testQuinticZero() {
53 final UnivariateDifferentiableFunction f = new QuinticFunction();
54 double result;
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56 NewtonRaphsonSolver solver = new NewtonRaphsonSolver();
57 result = solver.solve(100, f, -0.2, 0.2);
58 Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
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60 result = solver.solve(100, f, -0.1, 0.3);
61 Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
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63 result = solver.solve(100, f, -0.3, 0.45);
64 Assert.assertEquals(result, 0, solver.getAbsoluteAccuracy());
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66 result = solver.solve(100, f, 0.3, 0.7);
67 Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
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69 result = solver.solve(100, f, 0.2, 0.6);
70 Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
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72 result = solver.solve(100, f, 0.05, 0.95);
73 Assert.assertEquals(result, 0.5, solver.getAbsoluteAccuracy());
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75 result = solver.solve(100, f, 0.85, 1.25);
76 Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
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78 result = solver.solve(100, f, 0.8, 1.2);
79 Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
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81 result = solver.solve(100, f, 0.85, 1.75);
82 Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
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84 result = solver.solve(100, f, 0.55, 1.45);
85 Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
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87 result = solver.solve(100, f, 0.85, 5);
88 Assert.assertEquals(result, 1.0, solver.getAbsoluteAccuracy());
89 }
90 }