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    *      http://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  package org.apache.commons.nabla.forward;
18  
19  import org.apache.commons.math3.util.FastMath;
20  import org.apache.commons.nabla.AbstractMathTest;
21  import org.junit.Test;
22  
23  public class HypotGeneratorTest extends AbstractMathTest {
24  
25      @Test
26      public void testReference1(){
27          checkReference(new ReferenceFunction() {
28              public double value(double t) { return FastMath.hypot(t, 3.0); }
29              public double firstDerivative(double t) { return t / FastMath.hypot(t, 3.0); }
30          }, -2, 2, 50, 3.0e-16);
31      }
32  
33      @Test
34      public void testReference2(){
35          checkReference(new ReferenceFunction() {
36              public double value(double t) { return FastMath.hypot(3.0, t); }
37              public double firstDerivative(double t) { return t / FastMath.hypot(t, 3.0); }
38          }, -2, 2, 50, 3.0e-16);
39      }
40  
41      @Test
42      public void testReference12Aligned(){
43          checkReference(new ReferenceFunction() {
44              public double value(double t) { return FastMath.hypot(t, t); }
45              public double firstDerivative(double t) { return FastMath.sqrt(2); }
46          }, 0.1, 10, 20, 3.0e-16);
47      }
48  
49      @Test
50      public void testReference12Shifted(){
51          checkReference(new ReferenceFunction() {
52              public double value(double t) { return FastMath.hypot(t, t + 1); }
53              public double firstDerivative(double t) { return (2 * t + 1) / FastMath.hypot(t, t + 1); }
54          }, 0.1, 10, 20, 5.0e-16);
55      }
56  
57  }