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Java > Open Source Codes > org > apache > commons > math > special > ErfTest


1 /*
2  * Copyright 2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package org.apache.commons.math.special;
18
19 import org.apache.commons.math.MathException;
20
21 import junit.framework.TestCase;
22
23 /**
24  * @version $Revision$ $Date: 2005-02-26 05:11:52 -0800 (Sat, 26 Feb 2005) $
25  */
26 public class ErfTest extends TestCase {
27
28     public void testErf0() throws MathException {
29         double actual = Erf.erf(0.0);
30         double expected = 0.0;
31         assertEquals(expected, actual, 1.0e-5);
32     }
33
34     public void testErf1960() throws MathException {
35         double x = 1.960 / Math.sqrt(2.0);
36         double actual = Erf.erf(x);
37         double expected = 0.95;
38         assertEquals(expected, actual, 1.0e-5);
39
40         actual = Erf.erf(-x);
41         expected = -expected;
42         assertEquals(expected, actual, 1.0e-5);
43     }
44
45     public void testErf2576() throws MathException {
46         double x = 2.576 / Math.sqrt(2.0);
47         double actual = Erf.erf(x);
48         double expected = 0.99;
49         assertEquals(expected, actual, 1.0e-5);
50     
51         actual = Erf.erf(-x);
52         expected = -expected;
53         assertEquals(expected, actual, 1.0e-5);
54     }
55
56     public void testErf2807() throws MathException {
57         double x = 2.807 / Math.sqrt(2.0);
58         double actual = Erf.erf(x);
59         double expected = 0.995;
60         assertEquals(expected, actual, 1.0e-5);
61         
62         actual = Erf.erf(-x);
63         expected = -expected;
64         assertEquals(expected, actual, 1.0e-5);
65     }
66
67     public void testErf3291() throws MathException {
68         double x = 3.291 / Math.sqrt(2.0);
69         double actual = Erf.erf(x);
70         double expected = 0.999;
71         assertEquals(expected, actual, 1.0e-5);
72         
73         actual = Erf.erf(-x);
74         expected = -expected;
75         assertEquals(expected, actual, 1.0e-5);
76     }
77 }
78
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