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view libs/commons-math-2.1/docs/apidocs/src-html/org/apache/commons/math/ode/sampling/DummyStepInterpolator.html @ 13:cbf34dd4d7e6
commons-math-2.1 added
| author | dwinter |
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| date | Tue, 04 Jan 2011 10:02:07 +0100 |
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<HTML> <BODY BGCOLOR="white"> <PRE> <FONT color="green">001</FONT> /*<a name="line.1"></a> <FONT color="green">002</FONT> * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a> <FONT color="green">003</FONT> * contributor license agreements. See the NOTICE file distributed with<a name="line.3"></a> <FONT color="green">004</FONT> * this work for additional information regarding copyright ownership.<a name="line.4"></a> <FONT color="green">005</FONT> * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a> <FONT color="green">006</FONT> * (the "License"); you may not use this file except in compliance with<a name="line.6"></a> <FONT color="green">007</FONT> * the License. You may obtain a copy of the License at<a name="line.7"></a> <FONT color="green">008</FONT> *<a name="line.8"></a> <FONT color="green">009</FONT> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a> <FONT color="green">010</FONT> *<a name="line.10"></a> <FONT color="green">011</FONT> * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a> <FONT color="green">012</FONT> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a> <FONT color="green">013</FONT> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a> <FONT color="green">014</FONT> * See the License for the specific language governing permissions and<a name="line.14"></a> <FONT color="green">015</FONT> * limitations under the License.<a name="line.15"></a> <FONT color="green">016</FONT> */<a name="line.16"></a> <FONT color="green">017</FONT> <a name="line.17"></a> <FONT color="green">018</FONT> package org.apache.commons.math.ode.sampling;<a name="line.18"></a> <FONT color="green">019</FONT> <a name="line.19"></a> <FONT color="green">020</FONT> import java.io.IOException;<a name="line.20"></a> <FONT color="green">021</FONT> import java.io.ObjectInput;<a name="line.21"></a> <FONT color="green">022</FONT> import java.io.ObjectOutput;<a name="line.22"></a> <FONT color="green">023</FONT> <a name="line.23"></a> <FONT color="green">024</FONT> import org.apache.commons.math.ode.DerivativeException;<a name="line.24"></a> <FONT color="green">025</FONT> <a name="line.25"></a> <FONT color="green">026</FONT> /** This class is a step interpolator that does nothing.<a name="line.26"></a> <FONT color="green">027</FONT> *<a name="line.27"></a> <FONT color="green">028</FONT> * <p>This class is used when the {@link StepHandler "step handler"}<a name="line.28"></a> <FONT color="green">029</FONT> * set up by the user does not need step interpolation. It does not<a name="line.29"></a> <FONT color="green">030</FONT> * recompute the state when {@link AbstractStepInterpolator#setInterpolatedTime<a name="line.30"></a> <FONT color="green">031</FONT> * setInterpolatedTime} is called. This implies the interpolated state<a name="line.31"></a> <FONT color="green">032</FONT> * is always the state at the end of the current step.</p><a name="line.32"></a> <FONT color="green">033</FONT> *<a name="line.33"></a> <FONT color="green">034</FONT> * @see StepHandler<a name="line.34"></a> <FONT color="green">035</FONT> *<a name="line.35"></a> <FONT color="green">036</FONT> * @version $Revision: 919479 $ $Date: 2010-03-05 11:35:56 -0500 (Fri, 05 Mar 2010) $<a name="line.36"></a> <FONT color="green">037</FONT> * @since 1.2<a name="line.37"></a> <FONT color="green">038</FONT> */<a name="line.38"></a> <FONT color="green">039</FONT> <a name="line.39"></a> <FONT color="green">040</FONT> public class DummyStepInterpolator<a name="line.40"></a> <FONT color="green">041</FONT> extends AbstractStepInterpolator {<a name="line.41"></a> <FONT color="green">042</FONT> <a name="line.42"></a> <FONT color="green">043</FONT> /** Serializable version identifier. */<a name="line.43"></a> <FONT color="green">044</FONT> private static final long serialVersionUID = 1708010296707839488L;<a name="line.44"></a> <FONT color="green">045</FONT> <a name="line.45"></a> <FONT color="green">046</FONT> /** Current derivative. */<a name="line.46"></a> <FONT color="green">047</FONT> private double[] currentDerivative;<a name="line.47"></a> <FONT color="green">048</FONT> <a name="line.48"></a> <FONT color="green">049</FONT> /** Simple constructor.<a name="line.49"></a> <FONT color="green">050</FONT> * This constructor builds an instance that is not usable yet, the<a name="line.50"></a> <FONT color="green">051</FONT> * <code>AbstractStepInterpolator.reinitialize</code> protected method<a name="line.51"></a> <FONT color="green">052</FONT> * should be called before using the instance in order to initialize<a name="line.52"></a> <FONT color="green">053</FONT> * the internal arrays. This constructor is used only in order to delay<a name="line.53"></a> <FONT color="green">054</FONT> * the initialization in some cases. As an example, the {@link<a name="line.54"></a> <FONT color="green">055</FONT> * org.apache.commons.math.ode.nonstiff.EmbeddedRungeKuttaIntegrator} uses<a name="line.55"></a> <FONT color="green">056</FONT> * the prototyping design pattern to create the step interpolators by<a name="line.56"></a> <FONT color="green">057</FONT> * cloning an uninitialized model and latter initializing the copy.<a name="line.57"></a> <FONT color="green">058</FONT> */<a name="line.58"></a> <FONT color="green">059</FONT> public DummyStepInterpolator() {<a name="line.59"></a> <FONT color="green">060</FONT> super();<a name="line.60"></a> <FONT color="green">061</FONT> currentDerivative = null;<a name="line.61"></a> <FONT color="green">062</FONT> }<a name="line.62"></a> <FONT color="green">063</FONT> <a name="line.63"></a> <FONT color="green">064</FONT> /** Simple constructor.<a name="line.64"></a> <FONT color="green">065</FONT> * @param y reference to the integrator array holding the state at<a name="line.65"></a> <FONT color="green">066</FONT> * the end of the step<a name="line.66"></a> <FONT color="green">067</FONT> * @param yDot reference to the integrator array holding the state<a name="line.67"></a> <FONT color="green">068</FONT> * derivative at some arbitrary point within the step<a name="line.68"></a> <FONT color="green">069</FONT> * @param forward integration direction indicator<a name="line.69"></a> <FONT color="green">070</FONT> */<a name="line.70"></a> <FONT color="green">071</FONT> public DummyStepInterpolator(final double[] y, final double[] yDot, final boolean forward) {<a name="line.71"></a> <FONT color="green">072</FONT> super(y, forward);<a name="line.72"></a> <FONT color="green">073</FONT> currentDerivative = yDot;<a name="line.73"></a> <FONT color="green">074</FONT> }<a name="line.74"></a> <FONT color="green">075</FONT> <a name="line.75"></a> <FONT color="green">076</FONT> /** Copy constructor.<a name="line.76"></a> <FONT color="green">077</FONT> * @param interpolator interpolator to copy from. The copy is a deep<a name="line.77"></a> <FONT color="green">078</FONT> * copy: its arrays are separated from the original arrays of the<a name="line.78"></a> <FONT color="green">079</FONT> * instance<a name="line.79"></a> <FONT color="green">080</FONT> */<a name="line.80"></a> <FONT color="green">081</FONT> public DummyStepInterpolator(final DummyStepInterpolator interpolator) {<a name="line.81"></a> <FONT color="green">082</FONT> super(interpolator);<a name="line.82"></a> <FONT color="green">083</FONT> currentDerivative = interpolator.currentDerivative.clone();<a name="line.83"></a> <FONT color="green">084</FONT> }<a name="line.84"></a> <FONT color="green">085</FONT> <a name="line.85"></a> <FONT color="green">086</FONT> /** Really copy the finalized instance.<a name="line.86"></a> <FONT color="green">087</FONT> * @return a copy of the finalized instance<a name="line.87"></a> <FONT color="green">088</FONT> */<a name="line.88"></a> <FONT color="green">089</FONT> @Override<a name="line.89"></a> <FONT color="green">090</FONT> protected StepInterpolator doCopy() {<a name="line.90"></a> <FONT color="green">091</FONT> return new DummyStepInterpolator(this);<a name="line.91"></a> <FONT color="green">092</FONT> }<a name="line.92"></a> <FONT color="green">093</FONT> <a name="line.93"></a> <FONT color="green">094</FONT> /** Compute the state at the interpolated time.<a name="line.94"></a> <FONT color="green">095</FONT> * In this class, this method does nothing: the interpolated state<a name="line.95"></a> <FONT color="green">096</FONT> * is always the state at the end of the current step.<a name="line.96"></a> <FONT color="green">097</FONT> * @param theta normalized interpolation abscissa within the step<a name="line.97"></a> <FONT color="green">098</FONT> * (theta is zero at the previous time step and one at the current time step)<a name="line.98"></a> <FONT color="green">099</FONT> * @param oneMinusThetaH time gap between the interpolated time and<a name="line.99"></a> <FONT color="green">100</FONT> * the current time<a name="line.100"></a> <FONT color="green">101</FONT> * @throws DerivativeException this exception is propagated to the caller if the<a name="line.101"></a> <FONT color="green">102</FONT> * underlying user function triggers one<a name="line.102"></a> <FONT color="green">103</FONT> */<a name="line.103"></a> <FONT color="green">104</FONT> @Override<a name="line.104"></a> <FONT color="green">105</FONT> protected void computeInterpolatedStateAndDerivatives(final double theta, final double oneMinusThetaH)<a name="line.105"></a> <FONT color="green">106</FONT> throws DerivativeException {<a name="line.106"></a> <FONT color="green">107</FONT> System.arraycopy(currentState, 0, interpolatedState, 0, currentState.length);<a name="line.107"></a> <FONT color="green">108</FONT> System.arraycopy(currentDerivative, 0, interpolatedDerivatives, 0, currentDerivative.length);<a name="line.108"></a> <FONT color="green">109</FONT> }<a name="line.109"></a> <FONT color="green">110</FONT> <a name="line.110"></a> <FONT color="green">111</FONT> /** Write the instance to an output channel.<a name="line.111"></a> <FONT color="green">112</FONT> * @param out output channel<a name="line.112"></a> <FONT color="green">113</FONT> * @exception IOException if the instance cannot be written<a name="line.113"></a> <FONT color="green">114</FONT> */<a name="line.114"></a> <FONT color="green">115</FONT> @Override<a name="line.115"></a> <FONT color="green">116</FONT> public void writeExternal(final ObjectOutput out)<a name="line.116"></a> <FONT color="green">117</FONT> throws IOException {<a name="line.117"></a> <FONT color="green">118</FONT> <a name="line.118"></a> <FONT color="green">119</FONT> // save the state of the base class<a name="line.119"></a> <FONT color="green">120</FONT> writeBaseExternal(out);<a name="line.120"></a> <FONT color="green">121</FONT> <a name="line.121"></a> <FONT color="green">122</FONT> if (currentDerivative != null) {<a name="line.122"></a> <FONT color="green">123</FONT> for (int i = 0; i < currentDerivative.length; ++i) {<a name="line.123"></a> <FONT color="green">124</FONT> out.writeDouble(currentDerivative[i]);<a name="line.124"></a> <FONT color="green">125</FONT> }<a name="line.125"></a> <FONT color="green">126</FONT> }<a name="line.126"></a> <FONT color="green">127</FONT> <a name="line.127"></a> <FONT color="green">128</FONT> }<a name="line.128"></a> <FONT color="green">129</FONT> <a name="line.129"></a> <FONT color="green">130</FONT> /** Read the instance from an input channel.<a name="line.130"></a> <FONT color="green">131</FONT> * @param in input channel<a name="line.131"></a> <FONT color="green">132</FONT> * @exception IOException if the instance cannot be read<a name="line.132"></a> <FONT color="green">133</FONT> */<a name="line.133"></a> <FONT color="green">134</FONT> @Override<a name="line.134"></a> <FONT color="green">135</FONT> public void readExternal(final ObjectInput in)<a name="line.135"></a> <FONT color="green">136</FONT> throws IOException {<a name="line.136"></a> <FONT color="green">137</FONT> <a name="line.137"></a> <FONT color="green">138</FONT> // read the base class<a name="line.138"></a> <FONT color="green">139</FONT> final double t = readBaseExternal(in);<a name="line.139"></a> <FONT color="green">140</FONT> <a name="line.140"></a> <FONT color="green">141</FONT> if (currentState == null) {<a name="line.141"></a> <FONT color="green">142</FONT> currentDerivative = null;<a name="line.142"></a> <FONT color="green">143</FONT> } else {<a name="line.143"></a> <FONT color="green">144</FONT> currentDerivative = new double[currentState.length];<a name="line.144"></a> <FONT color="green">145</FONT> for (int i = 0; i < currentDerivative.length; ++i) {<a name="line.145"></a> <FONT color="green">146</FONT> currentDerivative[i] = in.readDouble();<a name="line.146"></a> <FONT color="green">147</FONT> }<a name="line.147"></a> <FONT color="green">148</FONT> }<a name="line.148"></a> <FONT color="green">149</FONT> <a name="line.149"></a> <FONT color="green">150</FONT> // we can now set the interpolated time and state<a name="line.150"></a> <FONT color="green">151</FONT> setInterpolatedTime(t);<a name="line.151"></a> <FONT color="green">152</FONT> <a name="line.152"></a> <FONT color="green">153</FONT> }<a name="line.153"></a> <FONT color="green">154</FONT> <a name="line.154"></a> <FONT color="green">155</FONT> }<a name="line.155"></a> </PRE> </BODY> </HTML>