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.util;
23
24 import org.hipparchus.exception.MathIllegalStateException;
25 import org.junit.Assert;
26 import org.junit.Test;
27
28 /**
29 * Tests for ContinuedFraction.
30 */
31 public class ContinuedFractionTest {
32
33 @Test
34 public void testGoldenRatio() throws Exception {
35 ContinuedFraction cf = new ContinuedFraction() {
36
37 @Override
38 public double getA(int n, double x) {
39 return 1.0;
40 }
41
42 @Override
43 public double getB(int n, double x) {
44 return 1.0;
45 }
46 };
47
48 double gr = cf.evaluate(0.0, 10e-9);
49 Assert.assertEquals(1.61803399, gr, 10e-9);
50 }
51
52 @Test(expected = MathIllegalStateException.class)
53 public void testNonConvergentContinuedFraction() {
54 ContinuedFraction cf = new ContinuedFraction() {
55
56 @Override
57 public double getA(int n, double x) {
58 return 1.0;
59 }
60
61 @Override
62 public double getB(int n, double x) {
63 return 1.0;
64 }
65
66 };
67
68 cf.evaluate(0.0, 10e-9, 10);
69 }
70
71 @Test(expected = MathIllegalStateException.class)
72 public void testInfinityDivergence() {
73 ContinuedFraction cf = new ContinuedFraction() {
74
75 @Override
76 public double getA(int n, double x) {
77 return 1. / n;
78 }
79
80 @Override
81 public double getB(int n, double x) {
82 return 1.0;
83 }
84
85 };
86
87 cf.evaluate(1);
88 }
89 }