|
13
|
1 <HTML>
|
|
|
2 <BODY BGCOLOR="white">
|
|
|
3 <PRE>
|
|
|
4 <FONT color="green">001</FONT> /*<a name="line.1"></a>
|
|
|
5 <FONT color="green">002</FONT> * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
|
|
|
6 <FONT color="green">003</FONT> * contributor license agreements. See the NOTICE file distributed with<a name="line.3"></a>
|
|
|
7 <FONT color="green">004</FONT> * this work for additional information regarding copyright ownership.<a name="line.4"></a>
|
|
|
8 <FONT color="green">005</FONT> * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
|
|
|
9 <FONT color="green">006</FONT> * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
|
|
|
10 <FONT color="green">007</FONT> * the License. You may obtain a copy of the License at<a name="line.7"></a>
|
|
|
11 <FONT color="green">008</FONT> *<a name="line.8"></a>
|
|
|
12 <FONT color="green">009</FONT> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
|
|
|
13 <FONT color="green">010</FONT> *<a name="line.10"></a>
|
|
|
14 <FONT color="green">011</FONT> * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
|
|
|
15 <FONT color="green">012</FONT> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
|
|
|
16 <FONT color="green">013</FONT> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
|
|
|
17 <FONT color="green">014</FONT> * See the License for the specific language governing permissions and<a name="line.14"></a>
|
|
|
18 <FONT color="green">015</FONT> * limitations under the License.<a name="line.15"></a>
|
|
|
19 <FONT color="green">016</FONT> */<a name="line.16"></a>
|
|
|
20 <FONT color="green">017</FONT> <a name="line.17"></a>
|
|
|
21 <FONT color="green">018</FONT> package org.apache.commons.math.ode.nonstiff;<a name="line.18"></a>
|
|
|
22 <FONT color="green">019</FONT> <a name="line.19"></a>
|
|
|
23 <FONT color="green">020</FONT> <a name="line.20"></a>
|
|
|
24 <FONT color="green">021</FONT> /**<a name="line.21"></a>
|
|
|
25 <FONT color="green">022</FONT> * This class implements the 3/8 fourth order Runge-Kutta<a name="line.22"></a>
|
|
|
26 <FONT color="green">023</FONT> * integrator for Ordinary Differential Equations.<a name="line.23"></a>
|
|
|
27 <FONT color="green">024</FONT> *<a name="line.24"></a>
|
|
|
28 <FONT color="green">025</FONT> * <p>This method is an explicit Runge-Kutta method, its Butcher-array<a name="line.25"></a>
|
|
|
29 <FONT color="green">026</FONT> * is the following one :<a name="line.26"></a>
|
|
|
30 <FONT color="green">027</FONT> * <pre><a name="line.27"></a>
|
|
|
31 <FONT color="green">028</FONT> * 0 | 0 0 0 0<a name="line.28"></a>
|
|
|
32 <FONT color="green">029</FONT> * 1/3 | 1/3 0 0 0<a name="line.29"></a>
|
|
|
33 <FONT color="green">030</FONT> * 2/3 |-1/3 1 0 0<a name="line.30"></a>
|
|
|
34 <FONT color="green">031</FONT> * 1 | 1 -1 1 0<a name="line.31"></a>
|
|
|
35 <FONT color="green">032</FONT> * |--------------------<a name="line.32"></a>
|
|
|
36 <FONT color="green">033</FONT> * | 1/8 3/8 3/8 1/8<a name="line.33"></a>
|
|
|
37 <FONT color="green">034</FONT> * </pre><a name="line.34"></a>
|
|
|
38 <FONT color="green">035</FONT> * </p><a name="line.35"></a>
|
|
|
39 <FONT color="green">036</FONT> *<a name="line.36"></a>
|
|
|
40 <FONT color="green">037</FONT> * @see EulerIntegrator<a name="line.37"></a>
|
|
|
41 <FONT color="green">038</FONT> * @see ClassicalRungeKuttaIntegrator<a name="line.38"></a>
|
|
|
42 <FONT color="green">039</FONT> * @see GillIntegrator<a name="line.39"></a>
|
|
|
43 <FONT color="green">040</FONT> * @see MidpointIntegrator<a name="line.40"></a>
|
|
|
44 <FONT color="green">041</FONT> * @version $Revision: 810196 $ $Date: 2009-09-01 15:47:46 -0400 (Tue, 01 Sep 2009) $<a name="line.41"></a>
|
|
|
45 <FONT color="green">042</FONT> * @since 1.2<a name="line.42"></a>
|
|
|
46 <FONT color="green">043</FONT> */<a name="line.43"></a>
|
|
|
47 <FONT color="green">044</FONT> <a name="line.44"></a>
|
|
|
48 <FONT color="green">045</FONT> public class ThreeEighthesIntegrator extends RungeKuttaIntegrator {<a name="line.45"></a>
|
|
|
49 <FONT color="green">046</FONT> <a name="line.46"></a>
|
|
|
50 <FONT color="green">047</FONT> /** Time steps Butcher array. */<a name="line.47"></a>
|
|
|
51 <FONT color="green">048</FONT> private static final double[] STATIC_C = {<a name="line.48"></a>
|
|
|
52 <FONT color="green">049</FONT> 1.0 / 3.0, 2.0 / 3.0, 1.0<a name="line.49"></a>
|
|
|
53 <FONT color="green">050</FONT> };<a name="line.50"></a>
|
|
|
54 <FONT color="green">051</FONT> <a name="line.51"></a>
|
|
|
55 <FONT color="green">052</FONT> /** Internal weights Butcher array. */<a name="line.52"></a>
|
|
|
56 <FONT color="green">053</FONT> private static final double[][] STATIC_A = {<a name="line.53"></a>
|
|
|
57 <FONT color="green">054</FONT> { 1.0 / 3.0 },<a name="line.54"></a>
|
|
|
58 <FONT color="green">055</FONT> { -1.0 / 3.0, 1.0 },<a name="line.55"></a>
|
|
|
59 <FONT color="green">056</FONT> { 1.0, -1.0, 1.0 }<a name="line.56"></a>
|
|
|
60 <FONT color="green">057</FONT> };<a name="line.57"></a>
|
|
|
61 <FONT color="green">058</FONT> <a name="line.58"></a>
|
|
|
62 <FONT color="green">059</FONT> /** Propagation weights Butcher array. */<a name="line.59"></a>
|
|
|
63 <FONT color="green">060</FONT> private static final double[] STATIC_B = {<a name="line.60"></a>
|
|
|
64 <FONT color="green">061</FONT> 1.0 / 8.0, 3.0 / 8.0, 3.0 / 8.0, 1.0 / 8.0<a name="line.61"></a>
|
|
|
65 <FONT color="green">062</FONT> };<a name="line.62"></a>
|
|
|
66 <FONT color="green">063</FONT> <a name="line.63"></a>
|
|
|
67 <FONT color="green">064</FONT> /** Simple constructor.<a name="line.64"></a>
|
|
|
68 <FONT color="green">065</FONT> * Build a 3/8 integrator with the given step.<a name="line.65"></a>
|
|
|
69 <FONT color="green">066</FONT> * @param step integration step<a name="line.66"></a>
|
|
|
70 <FONT color="green">067</FONT> */<a name="line.67"></a>
|
|
|
71 <FONT color="green">068</FONT> public ThreeEighthesIntegrator(final double step) {<a name="line.68"></a>
|
|
|
72 <FONT color="green">069</FONT> super("3/8", STATIC_C, STATIC_A, STATIC_B, new ThreeEighthesStepInterpolator(), step);<a name="line.69"></a>
|
|
|
73 <FONT color="green">070</FONT> }<a name="line.70"></a>
|
|
|
74 <FONT color="green">071</FONT> <a name="line.71"></a>
|
|
|
75 <FONT color="green">072</FONT> }<a name="line.72"></a>
|
|
|
76
|
|
|
77
|
|
|
78
|
|
|
79
|
|
|
80
|
|
|
81
|
|
|
82
|
|
|
83
|
|
|
84
|
|
|
85
|
|
|
86
|
|
|
87
|
|
|
88
|
|
|
89
|
|
|
90
|
|
|
91
|
|
|
92
|
|
|
93
|
|
|
94
|
|
|
95
|
|
|
96
|
|
|
97
|
|
|
98
|
|
|
99
|
|
|
100
|
|
|
101
|
|
|
102
|
|
|
103
|
|
|
104
|
|
|
105
|
|
|
106
|
|
|
107
|
|
|
108
|
|
|
109
|
|
|
110
|
|
|
111
|
|
|
112
|
|
|
113
|
|
|
114
|
|
|
115
|
|
|
116
|
|
|
117
|
|
|
118
|
|
|
119
|
|
|
120
|
|
|
121
|
|
|
122
|
|
|
123
|
|
|
124
|
|
|
125
|
|
|
126
|
|
|
127
|
|
|
128
|
|
|
129
|
|
|
130
|
|
|
131
|
|
|
132
|
|
|
133
|
|
|
134
|
|
|
135
|
|
|
136 </PRE>
|
|
|
137 </BODY>
|
|
|
138 </HTML>
|
