View Javadoc
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  
23  package org.hipparchus.complex;
24  
25  import org.hipparchus.UnitTestUtils;
26  import org.hipparchus.exception.MathIllegalArgumentException;
27  import org.hipparchus.util.FastMath;
28  import org.junit.Assert;
29  import org.junit.Test;
30  
31  /**
32   */
33  public class ComplexUtilsTest {
34  
35      private final double inf = Double.POSITIVE_INFINITY;
36      private final double negInf = Double.NEGATIVE_INFINITY;
37      private final double nan = Double.NaN;
38      private final double pi = FastMath.PI;
39  
40      private final Complex negInfInf = new Complex(negInf, inf);
41      private final Complex infNegInf = new Complex(inf, negInf);
42      private final Complex infInf = new Complex(inf, inf);
43      private final Complex negInfNegInf = new Complex(negInf, negInf);
44      private final Complex infNaN = new Complex(inf, nan);
45  
46      @Test
47      public void testPolar2Complex() {
48          UnitTestUtils.assertEquals(Complex.ONE,
49                  ComplexUtils.polar2Complex(1, 0), 10e-12);
50          UnitTestUtils.assertEquals(Complex.ZERO,
51                  ComplexUtils.polar2Complex(0, 1), 10e-12);
52          UnitTestUtils.assertEquals(Complex.ZERO,
53                  ComplexUtils.polar2Complex(0, -1), 10e-12);
54          UnitTestUtils.assertEquals(Complex.I,
55                  ComplexUtils.polar2Complex(1, pi/2), 10e-12);
56          UnitTestUtils.assertEquals(Complex.I.negate(),
57                  ComplexUtils.polar2Complex(1, -pi/2), 10e-12);
58          double r = 0;
59          for (int i = 0; i < 5; i++) {
60            r += i;
61            double theta = 0;
62            for (int j =0; j < 20; j++) {
63                theta += pi / 6;
64                UnitTestUtils.assertEquals(altPolar(r, theta),
65                        ComplexUtils.polar2Complex(r, theta), 10e-12);
66            }
67            theta = -2 * pi;
68            for (int j =0; j < 20; j++) {
69                theta -= pi / 6;
70                UnitTestUtils.assertEquals(altPolar(r, theta),
71                        ComplexUtils.polar2Complex(r, theta), 10e-12);
72            }
73          }
74      }
75  
76      protected Complex altPolar(double r, double theta) {
77          return Complex.I.multiply(new Complex(theta, 0)).exp().multiply(new Complex(r, 0));
78      }
79  
80      @Test(expected=MathIllegalArgumentException.class)
81      public void testPolar2ComplexIllegalModulus() {
82          ComplexUtils.polar2Complex(-1, 0);
83      }
84  
85      @Test
86      public void testPolar2ComplexNaN() {
87          UnitTestUtils.assertSame(Complex.NaN, ComplexUtils.polar2Complex(nan, 1));
88          UnitTestUtils.assertSame(Complex.NaN, ComplexUtils.polar2Complex(1, nan));
89          UnitTestUtils.assertSame(Complex.NaN,
90                  ComplexUtils.polar2Complex(nan, nan));
91      }
92  
93      @Test
94      public void testPolar2ComplexInf() {
95          UnitTestUtils.assertSame(Complex.NaN, ComplexUtils.polar2Complex(1, inf));
96          UnitTestUtils.assertSame(Complex.NaN,
97                  ComplexUtils.polar2Complex(1, negInf));
98          UnitTestUtils.assertSame(Complex.NaN, ComplexUtils.polar2Complex(inf, inf));
99          UnitTestUtils.assertSame(Complex.NaN,
100                 ComplexUtils.polar2Complex(inf, negInf));
101         UnitTestUtils.assertSame(infInf, ComplexUtils.polar2Complex(inf, pi/4));
102         UnitTestUtils.assertSame(infNaN, ComplexUtils.polar2Complex(inf, 0));
103         UnitTestUtils.assertSame(infNegInf, ComplexUtils.polar2Complex(inf, -pi/4));
104         UnitTestUtils.assertSame(negInfInf, ComplexUtils.polar2Complex(inf, 3*pi/4));
105         UnitTestUtils.assertSame(negInfNegInf, ComplexUtils.polar2Complex(inf, 5*pi/4));
106     }
107 
108     @Test
109     public void testConvertToComplex() {
110         final double[] real = new double[] { negInf, -123.45, 0, 1, 234.56, pi, inf };
111         final Complex[] complex = ComplexUtils.convertToComplex(real);
112 
113         for (int i = 0; i < real.length; i++) {
114             Assert.assertEquals(real[i], complex[i].getReal(), 0d);
115         }
116     }
117 }