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.integration.gauss;
23
24 import java.util.ArrayList;
25 import java.util.Collection;
26
27 import org.hipparchus.util.FastMath;
28 import org.junit.runner.RunWith;
29 import org.junit.runners.Parameterized;
30 import org.junit.runners.Parameterized.Parameters;
31
32 /**
33 * Test of the {@link HermiteRuleFactory}.
34 * This parameterized test extends the standard test for Gaussian quadrature
35 * rule, where each monomial is tested in turn.
36 * Parametrization allows to test automatically 0, 1, ... , {@link #MAX_NUM_POINTS}
37 * quadrature rules.
38 *
39 */
40 @RunWith(value=Parameterized.class)
41 public class HermiteParametricTest extends GaussianQuadratureAbstractTest {
42 private static final double SQRT_PI = FastMath.sqrt(Math.PI);
43 private static final GaussIntegratorFactory factory = new GaussIntegratorFactory();
44
45 /**
46 * The highest order quadrature rule to be tested.
47 */
48 public static final int MAX_NUM_POINTS = 30;
49
50 /**
51 * Creates a new instance of this test, with the specified number of nodes
52 * for the Gauss-Hermite quadrature rule.
53 *
54 * @param numberOfPoints Order of integration rule.
55 * @param maxDegree Maximum degree of monomials to be tested.
56 * @param eps Value of ε.
57 * @param numUlps Value of the maximum relative error (in ulps).
58 */
59 public HermiteParametricTest(int numberOfPoints,
60 int maxDegree,
61 double eps,
62 double numUlps) {
63 super(factory.hermite(numberOfPoints),
64 maxDegree, eps, numUlps);
65 }
66
67 /**
68 * Returns the collection of parameters to be passed to the constructor of
69 * this class.
70 * Gauss-Hermite quadrature rules of order 1, ..., {@link #MAX_NUM_POINTS}
71 * will be constructed.
72 *
73 * @return the collection of parameters for this parameterized test.
74 */
75 @Parameters
76 public static Collection<Object[]> getParameters() {
77 final ArrayList<Object[]> parameters = new ArrayList<Object[]>();
78 final int [] numUlps = {
79 10, 10, 10, 10, 20,
80 20, 20, 20, 30, 40,
81 40, 50, 150, 150, 150,
82 150, 150, 150, 150, 200,
83 250, 250, 300, 300, 300,
84 300, 300, 300, 350, 350
85 };
86 for (int k = 1; k <= MAX_NUM_POINTS; k++) {
87 parameters.add(new Object[] { k, 2 * k - 1, FastMath.ulp(1d), numUlps[k - 1] });
88 }
89 return parameters;
90 }
91
92 @Override
93 public double getExpectedValue(final int n) {
94 if (n % 2 == 1) {
95 return 0;
96 }
97
98 final int iMax = n / 2;
99 double p = 1;
100 double q = 1;
101 for (int i = 0; i < iMax; i++) {
102 p *= 2 * i + 1;
103 q *= 2;
104 }
105
106 return p / q * SQRT_PI;
107 }
108 }