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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.integration.gauss;
23  
24  import org.hipparchus.analysis.UnivariateFunction;
25  import org.hipparchus.analysis.function.Cos;
26  import org.hipparchus.analysis.function.Inverse;
27  import org.hipparchus.analysis.function.Log;
28  import org.junit.Assert;
29  import org.junit.Test;
30  
31  /**
32   * Test of the {@link FieldLegendreRuleFactory}.
33   *
34   */
35  public class LegendreHighPrecisionTest {
36      private static GaussIntegratorFactory factory = new GaussIntegratorFactory();
37  
38      @Test
39      public void testCos() {
40          final UnivariateFunction cos = new Cos();
41  
42          final GaussIntegrator integrator = factory.legendreHighPrecision(7, 0, Math.PI / 2);
43          final double s = integrator.integrate(cos);
44          // System.out.println("s=" + s + " e=" + 1);
45          Assert.assertEquals(1, s, Math.ulp(1d));
46      }
47  
48  
49      @Test
50      public void testInverse() {
51          final UnivariateFunction inv = new Inverse();
52          final UnivariateFunction log = new Log();
53  
54          final double lo = 12.34;
55          final double hi = 456.78;
56  
57          final GaussIntegrator integrator = factory.legendreHighPrecision(60, lo, hi);
58          final double s = integrator.integrate(inv);
59          final double expected = log.value(hi) - log.value(lo);
60          // System.out.println("s=" + s + " e=" + expected);
61          Assert.assertEquals(expected, s, 1e-15);
62      }
63  }