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| 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.MathRuntimeException;<a name="line.24"></a> <FONT color="green">025</FONT> import org.apache.commons.math.ode.DerivativeException;<a name="line.25"></a> <FONT color="green">026</FONT> <a name="line.26"></a> <FONT color="green">027</FONT> /** This abstract class represents an interpolator over the last step<a name="line.27"></a> <FONT color="green">028</FONT> * during an ODE integration.<a name="line.28"></a> <FONT color="green">029</FONT> *<a name="line.29"></a> <FONT color="green">030</FONT> * <p>The various ODE integrators provide objects extending this class<a name="line.30"></a> <FONT color="green">031</FONT> * to the step handlers. The handlers can use these objects to<a name="line.31"></a> <FONT color="green">032</FONT> * retrieve the state vector at intermediate times between the<a name="line.32"></a> <FONT color="green">033</FONT> * previous and the current grid points (dense output).</p><a name="line.33"></a> <FONT color="green">034</FONT> *<a name="line.34"></a> <FONT color="green">035</FONT> * @see org.apache.commons.math.ode.FirstOrderIntegrator<a name="line.35"></a> <FONT color="green">036</FONT> * @see org.apache.commons.math.ode.SecondOrderIntegrator<a name="line.36"></a> <FONT color="green">037</FONT> * @see StepHandler<a name="line.37"></a> <FONT color="green">038</FONT> *<a name="line.38"></a> <FONT color="green">039</FONT> * @version $Revision: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $<a name="line.39"></a> <FONT color="green">040</FONT> * @since 1.2<a name="line.40"></a> <FONT color="green">041</FONT> *<a name="line.41"></a> <FONT color="green">042</FONT> */<a name="line.42"></a> <FONT color="green">043</FONT> <a name="line.43"></a> <FONT color="green">044</FONT> public abstract class AbstractStepInterpolator<a name="line.44"></a> <FONT color="green">045</FONT> implements StepInterpolator {<a name="line.45"></a> <FONT color="green">046</FONT> <a name="line.46"></a> <FONT color="green">047</FONT> /** previous time */<a name="line.47"></a> <FONT color="green">048</FONT> protected double previousTime;<a name="line.48"></a> <FONT color="green">049</FONT> <a name="line.49"></a> <FONT color="green">050</FONT> /** current time */<a name="line.50"></a> <FONT color="green">051</FONT> protected double currentTime;<a name="line.51"></a> <FONT color="green">052</FONT> <a name="line.52"></a> <FONT color="green">053</FONT> /** current time step */<a name="line.53"></a> <FONT color="green">054</FONT> protected double h;<a name="line.54"></a> <FONT color="green">055</FONT> <a name="line.55"></a> <FONT color="green">056</FONT> /** current state */<a name="line.56"></a> <FONT color="green">057</FONT> protected double[] currentState;<a name="line.57"></a> <FONT color="green">058</FONT> <a name="line.58"></a> <FONT color="green">059</FONT> /** interpolated time */<a name="line.59"></a> <FONT color="green">060</FONT> protected double interpolatedTime;<a name="line.60"></a> <FONT color="green">061</FONT> <a name="line.61"></a> <FONT color="green">062</FONT> /** interpolated state */<a name="line.62"></a> <FONT color="green">063</FONT> protected double[] interpolatedState;<a name="line.63"></a> <FONT color="green">064</FONT> <a name="line.64"></a> <FONT color="green">065</FONT> /** interpolated derivatives */<a name="line.65"></a> <FONT color="green">066</FONT> protected double[] interpolatedDerivatives;<a name="line.66"></a> <FONT color="green">067</FONT> <a name="line.67"></a> <FONT color="green">068</FONT> /** indicate if the step has been finalized or not. */<a name="line.68"></a> <FONT color="green">069</FONT> private boolean finalized;<a name="line.69"></a> <FONT color="green">070</FONT> <a name="line.70"></a> <FONT color="green">071</FONT> /** integration direction. */<a name="line.71"></a> <FONT color="green">072</FONT> private boolean forward;<a name="line.72"></a> <FONT color="green">073</FONT> <a name="line.73"></a> <FONT color="green">074</FONT> /** indicator for dirty state. */<a name="line.74"></a> <FONT color="green">075</FONT> private boolean dirtyState;<a name="line.75"></a> <FONT color="green">076</FONT> <a name="line.76"></a> <FONT color="green">077</FONT> <a name="line.77"></a> <FONT color="green">078</FONT> /** Simple constructor.<a name="line.78"></a> <FONT color="green">079</FONT> * This constructor builds an instance that is not usable yet, the<a name="line.79"></a> <FONT color="green">080</FONT> * {@link #reinitialize} method should be called before using the<a name="line.80"></a> <FONT color="green">081</FONT> * instance in order to initialize the internal arrays. This<a name="line.81"></a> <FONT color="green">082</FONT> * constructor is used only in order to delay the initialization in<a name="line.82"></a> <FONT color="green">083</FONT> * some cases. As an example, the {@link<a name="line.83"></a> <FONT color="green">084</FONT> * org.apache.commons.math.ode.nonstiff.EmbeddedRungeKuttaIntegrator}<a name="line.84"></a> <FONT color="green">085</FONT> * class uses the prototyping design pattern to create the step<a name="line.85"></a> <FONT color="green">086</FONT> * interpolators by cloning an uninitialized model and latter<a name="line.86"></a> <FONT color="green">087</FONT> * initializing the copy.<a name="line.87"></a> <FONT color="green">088</FONT> */<a name="line.88"></a> <FONT color="green">089</FONT> protected AbstractStepInterpolator() {<a name="line.89"></a> <FONT color="green">090</FONT> previousTime = Double.NaN;<a name="line.90"></a> <FONT color="green">091</FONT> currentTime = Double.NaN;<a name="line.91"></a> <FONT color="green">092</FONT> h = Double.NaN;<a name="line.92"></a> <FONT color="green">093</FONT> interpolatedTime = Double.NaN;<a name="line.93"></a> <FONT color="green">094</FONT> currentState = null;<a name="line.94"></a> <FONT color="green">095</FONT> interpolatedState = null;<a name="line.95"></a> <FONT color="green">096</FONT> interpolatedDerivatives = null;<a name="line.96"></a> <FONT color="green">097</FONT> finalized = false;<a name="line.97"></a> <FONT color="green">098</FONT> this.forward = true;<a name="line.98"></a> <FONT color="green">099</FONT> this.dirtyState = true;<a name="line.99"></a> <FONT color="green">100</FONT> }<a name="line.100"></a> <FONT color="green">101</FONT> <a name="line.101"></a> <FONT color="green">102</FONT> /** Simple constructor.<a name="line.102"></a> <FONT color="green">103</FONT> * @param y reference to the integrator array holding the state at<a name="line.103"></a> <FONT color="green">104</FONT> * the end of the step<a name="line.104"></a> <FONT color="green">105</FONT> * @param forward integration direction indicator<a name="line.105"></a> <FONT color="green">106</FONT> */<a name="line.106"></a> <FONT color="green">107</FONT> protected AbstractStepInterpolator(final double[] y, final boolean forward) {<a name="line.107"></a> <FONT color="green">108</FONT> <a name="line.108"></a> <FONT color="green">109</FONT> previousTime = Double.NaN;<a name="line.109"></a> <FONT color="green">110</FONT> currentTime = Double.NaN;<a name="line.110"></a> <FONT color="green">111</FONT> h = Double.NaN;<a name="line.111"></a> <FONT color="green">112</FONT> interpolatedTime = Double.NaN;<a name="line.112"></a> <FONT color="green">113</FONT> <a name="line.113"></a> <FONT color="green">114</FONT> currentState = y;<a name="line.114"></a> <FONT color="green">115</FONT> interpolatedState = new double[y.length];<a name="line.115"></a> <FONT color="green">116</FONT> interpolatedDerivatives = new double[y.length];<a name="line.116"></a> <FONT color="green">117</FONT> <a name="line.117"></a> <FONT color="green">118</FONT> finalized = false;<a name="line.118"></a> <FONT color="green">119</FONT> this.forward = forward;<a name="line.119"></a> <FONT color="green">120</FONT> this.dirtyState = true;<a name="line.120"></a> <FONT color="green">121</FONT> <a name="line.121"></a> <FONT color="green">122</FONT> }<a name="line.122"></a> <FONT color="green">123</FONT> <a name="line.123"></a> <FONT color="green">124</FONT> /** Copy constructor.<a name="line.124"></a> <FONT color="green">125</FONT> <a name="line.125"></a> <FONT color="green">126</FONT> * <p>The copied interpolator should have been finalized before the<a name="line.126"></a> <FONT color="green">127</FONT> * copy, otherwise the copy will not be able to perform correctly<a name="line.127"></a> <FONT color="green">128</FONT> * any derivative computation and will throw a {@link<a name="line.128"></a> <FONT color="green">129</FONT> * NullPointerException} later. Since we don't want this constructor<a name="line.129"></a> <FONT color="green">130</FONT> * to throw the exceptions finalization may involve and since we<a name="line.130"></a> <FONT color="green">131</FONT> * don't want this method to modify the state of the copied<a name="line.131"></a> <FONT color="green">132</FONT> * interpolator, finalization is <strong>not</strong> done<a name="line.132"></a> <FONT color="green">133</FONT> * automatically, it remains under user control.</p><a name="line.133"></a> <FONT color="green">134</FONT> <a name="line.134"></a> <FONT color="green">135</FONT> * <p>The copy is a deep copy: its arrays are separated from the<a name="line.135"></a> <FONT color="green">136</FONT> * original arrays of the instance.</p><a name="line.136"></a> <FONT color="green">137</FONT> <a name="line.137"></a> <FONT color="green">138</FONT> * @param interpolator interpolator to copy from.<a name="line.138"></a> <FONT color="green">139</FONT> <a name="line.139"></a> <FONT color="green">140</FONT> */<a name="line.140"></a> <FONT color="green">141</FONT> protected AbstractStepInterpolator(final AbstractStepInterpolator interpolator) {<a name="line.141"></a> <FONT color="green">142</FONT> <a name="line.142"></a> <FONT color="green">143</FONT> previousTime = interpolator.previousTime;<a name="line.143"></a> <FONT color="green">144</FONT> currentTime = interpolator.currentTime;<a name="line.144"></a> <FONT color="green">145</FONT> h = interpolator.h;<a name="line.145"></a> <FONT color="green">146</FONT> interpolatedTime = interpolator.interpolatedTime;<a name="line.146"></a> <FONT color="green">147</FONT> <a name="line.147"></a> <FONT color="green">148</FONT> if (interpolator.currentState != null) {<a name="line.148"></a> <FONT color="green">149</FONT> currentState = interpolator.currentState.clone();<a name="line.149"></a> <FONT color="green">150</FONT> interpolatedState = interpolator.interpolatedState.clone();<a name="line.150"></a> <FONT color="green">151</FONT> interpolatedDerivatives = interpolator.interpolatedDerivatives.clone();<a name="line.151"></a> <FONT color="green">152</FONT> } else {<a name="line.152"></a> <FONT color="green">153</FONT> currentState = null;<a name="line.153"></a> <FONT color="green">154</FONT> interpolatedState = null;<a name="line.154"></a> <FONT color="green">155</FONT> interpolatedDerivatives = null;<a name="line.155"></a> <FONT color="green">156</FONT> }<a name="line.156"></a> <FONT color="green">157</FONT> <a name="line.157"></a> <FONT color="green">158</FONT> finalized = interpolator.finalized;<a name="line.158"></a> <FONT color="green">159</FONT> forward = interpolator.forward;<a name="line.159"></a> <FONT color="green">160</FONT> dirtyState = interpolator.dirtyState;<a name="line.160"></a> <FONT color="green">161</FONT> <a name="line.161"></a> <FONT color="green">162</FONT> }<a name="line.162"></a> <FONT color="green">163</FONT> <a name="line.163"></a> <FONT color="green">164</FONT> /** Reinitialize the instance<a name="line.164"></a> <FONT color="green">165</FONT> * @param y reference to the integrator array holding the state at<a name="line.165"></a> <FONT color="green">166</FONT> * the end of the step<a name="line.166"></a> <FONT color="green">167</FONT> * @param isForward integration direction indicator<a name="line.167"></a> <FONT color="green">168</FONT> */<a name="line.168"></a> <FONT color="green">169</FONT> protected void reinitialize(final double[] y, final boolean isForward) {<a name="line.169"></a> <FONT color="green">170</FONT> <a name="line.170"></a> <FONT color="green">171</FONT> previousTime = Double.NaN;<a name="line.171"></a> <FONT color="green">172</FONT> currentTime = Double.NaN;<a name="line.172"></a> <FONT color="green">173</FONT> h = Double.NaN;<a name="line.173"></a> <FONT color="green">174</FONT> interpolatedTime = Double.NaN;<a name="line.174"></a> <FONT color="green">175</FONT> <a name="line.175"></a> <FONT color="green">176</FONT> currentState = y;<a name="line.176"></a> <FONT color="green">177</FONT> interpolatedState = new double[y.length];<a name="line.177"></a> <FONT color="green">178</FONT> interpolatedDerivatives = new double[y.length];<a name="line.178"></a> <FONT color="green">179</FONT> <a name="line.179"></a> <FONT color="green">180</FONT> finalized = false;<a name="line.180"></a> <FONT color="green">181</FONT> this.forward = isForward;<a name="line.181"></a> <FONT color="green">182</FONT> this.dirtyState = true;<a name="line.182"></a> <FONT color="green">183</FONT> <a name="line.183"></a> <FONT color="green">184</FONT> }<a name="line.184"></a> <FONT color="green">185</FONT> <a name="line.185"></a> <FONT color="green">186</FONT> /** {@inheritDoc} */<a name="line.186"></a> <FONT color="green">187</FONT> public StepInterpolator copy() throws DerivativeException {<a name="line.187"></a> <FONT color="green">188</FONT> <a name="line.188"></a> <FONT color="green">189</FONT> // finalize the step before performing copy<a name="line.189"></a> <FONT color="green">190</FONT> finalizeStep();<a name="line.190"></a> <FONT color="green">191</FONT> <a name="line.191"></a> <FONT color="green">192</FONT> // create the new independent instance<a name="line.192"></a> <FONT color="green">193</FONT> return doCopy();<a name="line.193"></a> <FONT color="green">194</FONT> <a name="line.194"></a> <FONT color="green">195</FONT> }<a name="line.195"></a> <FONT color="green">196</FONT> <a name="line.196"></a> <FONT color="green">197</FONT> /** Really copy the finalized instance.<a name="line.197"></a> <FONT color="green">198</FONT> * <p>This method is called by {@link #copy()} after the<a name="line.198"></a> <FONT color="green">199</FONT> * step has been finalized. It must perform a deep copy<a name="line.199"></a> <FONT color="green">200</FONT> * to have an new instance completely independent for the<a name="line.200"></a> <FONT color="green">201</FONT> * original instance.<a name="line.201"></a> <FONT color="green">202</FONT> * @return a copy of the finalized instance<a name="line.202"></a> <FONT color="green">203</FONT> */<a name="line.203"></a> <FONT color="green">204</FONT> protected abstract StepInterpolator doCopy();<a name="line.204"></a> <FONT color="green">205</FONT> <a name="line.205"></a> <FONT color="green">206</FONT> /** Shift one step forward.<a name="line.206"></a> <FONT color="green">207</FONT> * Copy the current time into the previous time, hence preparing the<a name="line.207"></a> <FONT color="green">208</FONT> * interpolator for future calls to {@link #storeTime storeTime}<a name="line.208"></a> <FONT color="green">209</FONT> */<a name="line.209"></a> <FONT color="green">210</FONT> public void shift() {<a name="line.210"></a> <FONT color="green">211</FONT> previousTime = currentTime;<a name="line.211"></a> <FONT color="green">212</FONT> }<a name="line.212"></a> <FONT color="green">213</FONT> <a name="line.213"></a> <FONT color="green">214</FONT> /** Store the current step time.<a name="line.214"></a> <FONT color="green">215</FONT> * @param t current time<a name="line.215"></a> <FONT color="green">216</FONT> */<a name="line.216"></a> <FONT color="green">217</FONT> public void storeTime(final double t) {<a name="line.217"></a> <FONT color="green">218</FONT> <a name="line.218"></a> <FONT color="green">219</FONT> currentTime = t;<a name="line.219"></a> <FONT color="green">220</FONT> h = currentTime - previousTime;<a name="line.220"></a> <FONT color="green">221</FONT> setInterpolatedTime(t);<a name="line.221"></a> <FONT color="green">222</FONT> <a name="line.222"></a> <FONT color="green">223</FONT> // the step is not finalized anymore<a name="line.223"></a> <FONT color="green">224</FONT> finalized = false;<a name="line.224"></a> <FONT color="green">225</FONT> <a name="line.225"></a> <FONT color="green">226</FONT> }<a name="line.226"></a> <FONT color="green">227</FONT> <a name="line.227"></a> <FONT color="green">228</FONT> /** {@inheritDoc} */<a name="line.228"></a> <FONT color="green">229</FONT> public double getPreviousTime() {<a name="line.229"></a> <FONT color="green">230</FONT> return previousTime;<a name="line.230"></a> <FONT color="green">231</FONT> }<a name="line.231"></a> <FONT color="green">232</FONT> <a name="line.232"></a> <FONT color="green">233</FONT> /** {@inheritDoc} */<a name="line.233"></a> <FONT color="green">234</FONT> public double getCurrentTime() {<a name="line.234"></a> <FONT color="green">235</FONT> return currentTime;<a name="line.235"></a> <FONT color="green">236</FONT> }<a name="line.236"></a> <FONT color="green">237</FONT> <a name="line.237"></a> <FONT color="green">238</FONT> /** {@inheritDoc} */<a name="line.238"></a> <FONT color="green">239</FONT> public double getInterpolatedTime() {<a name="line.239"></a> <FONT color="green">240</FONT> return interpolatedTime;<a name="line.240"></a> <FONT color="green">241</FONT> }<a name="line.241"></a> <FONT color="green">242</FONT> <a name="line.242"></a> <FONT color="green">243</FONT> /** {@inheritDoc} */<a name="line.243"></a> <FONT color="green">244</FONT> public void setInterpolatedTime(final double time) {<a name="line.244"></a> <FONT color="green">245</FONT> interpolatedTime = time;<a name="line.245"></a> <FONT color="green">246</FONT> dirtyState = true;<a name="line.246"></a> <FONT color="green">247</FONT> }<a name="line.247"></a> <FONT color="green">248</FONT> <a name="line.248"></a> <FONT color="green">249</FONT> /** {@inheritDoc} */<a name="line.249"></a> <FONT color="green">250</FONT> public boolean isForward() {<a name="line.250"></a> <FONT color="green">251</FONT> return forward;<a name="line.251"></a> <FONT color="green">252</FONT> }<a name="line.252"></a> <FONT color="green">253</FONT> <a name="line.253"></a> <FONT color="green">254</FONT> /** Compute the state and derivatives at the interpolated time.<a name="line.254"></a> <FONT color="green">255</FONT> * This is the main processing method that should be implemented by<a name="line.255"></a> <FONT color="green">256</FONT> * the derived classes to perform the interpolation.<a name="line.256"></a> <FONT color="green">257</FONT> * @param theta normalized interpolation abscissa within the step<a name="line.257"></a> <FONT color="green">258</FONT> * (theta is zero at the previous time step and one at the current time step)<a name="line.258"></a> <FONT color="green">259</FONT> * @param oneMinusThetaH time gap between the interpolated time and<a name="line.259"></a> <FONT color="green">260</FONT> * the current time<a name="line.260"></a> <FONT color="green">261</FONT> * @throws DerivativeException this exception is propagated to the caller if the<a name="line.261"></a> <FONT color="green">262</FONT> * underlying user function triggers one<a name="line.262"></a> <FONT color="green">263</FONT> */<a name="line.263"></a> <FONT color="green">264</FONT> protected abstract void computeInterpolatedStateAndDerivatives(double theta,<a name="line.264"></a> <FONT color="green">265</FONT> double oneMinusThetaH)<a name="line.265"></a> <FONT color="green">266</FONT> throws DerivativeException;<a name="line.266"></a> <FONT color="green">267</FONT> <a name="line.267"></a> <FONT color="green">268</FONT> /** {@inheritDoc} */<a name="line.268"></a> <FONT color="green">269</FONT> public double[] getInterpolatedState() throws DerivativeException {<a name="line.269"></a> <FONT color="green">270</FONT> <a name="line.270"></a> <FONT color="green">271</FONT> // lazy evaluation of the state<a name="line.271"></a> <FONT color="green">272</FONT> if (dirtyState) {<a name="line.272"></a> <FONT color="green">273</FONT> final double oneMinusThetaH = currentTime - interpolatedTime;<a name="line.273"></a> <FONT color="green">274</FONT> final double theta = (h == 0) ? 0 : (h - oneMinusThetaH) / h;<a name="line.274"></a> <FONT color="green">275</FONT> computeInterpolatedStateAndDerivatives(theta, oneMinusThetaH);<a name="line.275"></a> <FONT color="green">276</FONT> dirtyState = false;<a name="line.276"></a> <FONT color="green">277</FONT> }<a name="line.277"></a> <FONT color="green">278</FONT> <a name="line.278"></a> <FONT color="green">279</FONT> return interpolatedState;<a name="line.279"></a> <FONT color="green">280</FONT> <a name="line.280"></a> <FONT color="green">281</FONT> }<a name="line.281"></a> <FONT color="green">282</FONT> <a name="line.282"></a> <FONT color="green">283</FONT> /** {@inheritDoc} */<a name="line.283"></a> <FONT color="green">284</FONT> public double[] getInterpolatedDerivatives() throws DerivativeException {<a name="line.284"></a> <FONT color="green">285</FONT> <a name="line.285"></a> <FONT color="green">286</FONT> // lazy evaluation of the state<a name="line.286"></a> <FONT color="green">287</FONT> if (dirtyState) {<a name="line.287"></a> <FONT color="green">288</FONT> final double oneMinusThetaH = currentTime - interpolatedTime;<a name="line.288"></a> <FONT color="green">289</FONT> final double theta = (h == 0) ? 0 : (h - oneMinusThetaH) / h;<a name="line.289"></a> <FONT color="green">290</FONT> computeInterpolatedStateAndDerivatives(theta, oneMinusThetaH);<a name="line.290"></a> <FONT color="green">291</FONT> dirtyState = false;<a name="line.291"></a> <FONT color="green">292</FONT> }<a name="line.292"></a> <FONT color="green">293</FONT> <a name="line.293"></a> <FONT color="green">294</FONT> return interpolatedDerivatives;<a name="line.294"></a> <FONT color="green">295</FONT> <a name="line.295"></a> <FONT color="green">296</FONT> }<a name="line.296"></a> <FONT color="green">297</FONT> <a name="line.297"></a> <FONT color="green">298</FONT> /**<a name="line.298"></a> <FONT color="green">299</FONT> * Finalize the step.<a name="line.299"></a> <FONT color="green">300</FONT> <a name="line.300"></a> <FONT color="green">301</FONT> * <p>Some embedded Runge-Kutta integrators need fewer functions<a name="line.301"></a> <FONT color="green">302</FONT> * evaluations than their counterpart step interpolators. These<a name="line.302"></a> <FONT color="green">303</FONT> * interpolators should perform the last evaluations they need by<a name="line.303"></a> <FONT color="green">304</FONT> * themselves only if they need them. This method triggers these<a name="line.304"></a> <FONT color="green">305</FONT> * extra evaluations. It can be called directly by the user step<a name="line.305"></a> <FONT color="green">306</FONT> * handler and it is called automatically if {@link<a name="line.306"></a> <FONT color="green">307</FONT> * #setInterpolatedTime} is called.</p><a name="line.307"></a> <FONT color="green">308</FONT> <a name="line.308"></a> <FONT color="green">309</FONT> * <p>Once this method has been called, <strong>no</strong> other<a name="line.309"></a> <FONT color="green">310</FONT> * evaluation will be performed on this step. If there is a need to<a name="line.310"></a> <FONT color="green">311</FONT> * have some side effects between the step handler and the<a name="line.311"></a> <FONT color="green">312</FONT> * differential equations (for example update some data in the<a name="line.312"></a> <FONT color="green">313</FONT> * equations once the step has been done), it is advised to call<a name="line.313"></a> <FONT color="green">314</FONT> * this method explicitly from the step handler before these side<a name="line.314"></a> <FONT color="green">315</FONT> * effects are set up. If the step handler induces no side effect,<a name="line.315"></a> <FONT color="green">316</FONT> * then this method can safely be ignored, it will be called<a name="line.316"></a> <FONT color="green">317</FONT> * transparently as needed.</p><a name="line.317"></a> <FONT color="green">318</FONT> <a name="line.318"></a> <FONT color="green">319</FONT> * <p><strong>Warning</strong>: since the step interpolator provided<a name="line.319"></a> <FONT color="green">320</FONT> * to the step handler as a parameter of the {@link<a name="line.320"></a> <FONT color="green">321</FONT> * StepHandler#handleStep handleStep} is valid only for the duration<a name="line.321"></a> <FONT color="green">322</FONT> * of the {@link StepHandler#handleStep handleStep} call, one cannot<a name="line.322"></a> <FONT color="green">323</FONT> * simply store a reference and reuse it later. One should first<a name="line.323"></a> <FONT color="green">324</FONT> * finalize the instance, then copy this finalized instance into a<a name="line.324"></a> <FONT color="green">325</FONT> * new object that can be kept.</p><a name="line.325"></a> <FONT color="green">326</FONT> <a name="line.326"></a> <FONT color="green">327</FONT> * <p>This method calls the protected <code>doFinalize</code> method<a name="line.327"></a> <FONT color="green">328</FONT> * if it has never been called during this step and set a flag<a name="line.328"></a> <FONT color="green">329</FONT> * indicating that it has been called once. It is the <code><a name="line.329"></a> <FONT color="green">330</FONT> * doFinalize</code> method which should perform the evaluations.<a name="line.330"></a> <FONT color="green">331</FONT> * This wrapping prevents from calling <code>doFinalize</code> several<a name="line.331"></a> <FONT color="green">332</FONT> * times and hence evaluating the differential equations too often.<a name="line.332"></a> <FONT color="green">333</FONT> * Therefore, subclasses are not allowed not reimplement it, they<a name="line.333"></a> <FONT color="green">334</FONT> * should rather reimplement <code>doFinalize</code>.</p><a name="line.334"></a> <FONT color="green">335</FONT> <a name="line.335"></a> <FONT color="green">336</FONT> * @throws DerivativeException this exception is propagated to the<a name="line.336"></a> <FONT color="green">337</FONT> * caller if the underlying user function triggers one<a name="line.337"></a> <FONT color="green">338</FONT> */<a name="line.338"></a> <FONT color="green">339</FONT> public final void finalizeStep()<a name="line.339"></a> <FONT color="green">340</FONT> throws DerivativeException {<a name="line.340"></a> <FONT color="green">341</FONT> if (! finalized) {<a name="line.341"></a> <FONT color="green">342</FONT> doFinalize();<a name="line.342"></a> <FONT color="green">343</FONT> finalized = true;<a name="line.343"></a> <FONT color="green">344</FONT> }<a name="line.344"></a> <FONT color="green">345</FONT> }<a name="line.345"></a> <FONT color="green">346</FONT> <a name="line.346"></a> <FONT color="green">347</FONT> /**<a name="line.347"></a> <FONT color="green">348</FONT> * Really finalize the step.<a name="line.348"></a> <FONT color="green">349</FONT> * The default implementation of this method does nothing.<a name="line.349"></a> <FONT color="green">350</FONT> * @throws DerivativeException this exception is propagated to the<a name="line.350"></a> <FONT color="green">351</FONT> * caller if the underlying user function triggers one<a name="line.351"></a> <FONT color="green">352</FONT> */<a name="line.352"></a> <FONT color="green">353</FONT> protected void doFinalize()<a name="line.353"></a> <FONT color="green">354</FONT> throws DerivativeException {<a name="line.354"></a> <FONT color="green">355</FONT> }<a name="line.355"></a> <FONT color="green">356</FONT> <a name="line.356"></a> <FONT color="green">357</FONT> /** {@inheritDoc} */<a name="line.357"></a> <FONT color="green">358</FONT> public abstract void writeExternal(ObjectOutput out)<a name="line.358"></a> <FONT color="green">359</FONT> throws IOException;<a name="line.359"></a> <FONT color="green">360</FONT> <a name="line.360"></a> <FONT color="green">361</FONT> /** {@inheritDoc} */<a name="line.361"></a> <FONT color="green">362</FONT> public abstract void readExternal(ObjectInput in)<a name="line.362"></a> <FONT color="green">363</FONT> throws IOException, ClassNotFoundException;<a name="line.363"></a> <FONT color="green">364</FONT> <a name="line.364"></a> <FONT color="green">365</FONT> /** Save the base state of the instance.<a name="line.365"></a> <FONT color="green">366</FONT> * This method performs step finalization if it has not been done<a name="line.366"></a> <FONT color="green">367</FONT> * before.<a name="line.367"></a> <FONT color="green">368</FONT> * @param out stream where to save the state<a name="line.368"></a> <FONT color="green">369</FONT> * @exception IOException in case of write error<a name="line.369"></a> <FONT color="green">370</FONT> */<a name="line.370"></a> <FONT color="green">371</FONT> protected void writeBaseExternal(final ObjectOutput out)<a name="line.371"></a> <FONT color="green">372</FONT> throws IOException {<a name="line.372"></a> <FONT color="green">373</FONT> <a name="line.373"></a> <FONT color="green">374</FONT> if (currentState == null) {<a name="line.374"></a> <FONT color="green">375</FONT> out.writeInt(-1);<a name="line.375"></a> <FONT color="green">376</FONT> } else {<a name="line.376"></a> <FONT color="green">377</FONT> out.writeInt(currentState.length);<a name="line.377"></a> <FONT color="green">378</FONT> }<a name="line.378"></a> <FONT color="green">379</FONT> out.writeDouble(previousTime);<a name="line.379"></a> <FONT color="green">380</FONT> out.writeDouble(currentTime);<a name="line.380"></a> <FONT color="green">381</FONT> out.writeDouble(h);<a name="line.381"></a> <FONT color="green">382</FONT> out.writeBoolean(forward);<a name="line.382"></a> <FONT color="green">383</FONT> <a name="line.383"></a> <FONT color="green">384</FONT> if (currentState != null) {<a name="line.384"></a> <FONT color="green">385</FONT> for (int i = 0; i < currentState.length; ++i) {<a name="line.385"></a> <FONT color="green">386</FONT> out.writeDouble(currentState[i]);<a name="line.386"></a> <FONT color="green">387</FONT> }<a name="line.387"></a> <FONT color="green">388</FONT> }<a name="line.388"></a> <FONT color="green">389</FONT> <a name="line.389"></a> <FONT color="green">390</FONT> out.writeDouble(interpolatedTime);<a name="line.390"></a> <FONT color="green">391</FONT> <a name="line.391"></a> <FONT color="green">392</FONT> // we do not store the interpolated state,<a name="line.392"></a> <FONT color="green">393</FONT> // it will be recomputed as needed after reading<a name="line.393"></a> <FONT color="green">394</FONT> <a name="line.394"></a> <FONT color="green">395</FONT> // finalize the step (and don't bother saving the now true flag)<a name="line.395"></a> <FONT color="green">396</FONT> try {<a name="line.396"></a> <FONT color="green">397</FONT> finalizeStep();<a name="line.397"></a> <FONT color="green">398</FONT> } catch (DerivativeException e) {<a name="line.398"></a> <FONT color="green">399</FONT> throw MathRuntimeException.createIOException(e);<a name="line.399"></a> <FONT color="green">400</FONT> }<a name="line.400"></a> <FONT color="green">401</FONT> <a name="line.401"></a> <FONT color="green">402</FONT> }<a name="line.402"></a> <FONT color="green">403</FONT> <a name="line.403"></a> <FONT color="green">404</FONT> /** Read the base state of the instance.<a name="line.404"></a> <FONT color="green">405</FONT> * This method does <strong>neither</strong> set the interpolated<a name="line.405"></a> <FONT color="green">406</FONT> * time nor state. It is up to the derived class to reset it<a name="line.406"></a> <FONT color="green">407</FONT> * properly calling the {@link #setInterpolatedTime} method later,<a name="line.407"></a> <FONT color="green">408</FONT> * once all rest of the object state has been set up properly.<a name="line.408"></a> <FONT color="green">409</FONT> * @param in stream where to read the state from<a name="line.409"></a> <FONT color="green">410</FONT> * @return interpolated time be set later by the caller<a name="line.410"></a> <FONT color="green">411</FONT> * @exception IOException in case of read error<a name="line.411"></a> <FONT color="green">412</FONT> */<a name="line.412"></a> <FONT color="green">413</FONT> protected double readBaseExternal(final ObjectInput in)<a name="line.413"></a> <FONT color="green">414</FONT> throws IOException {<a name="line.414"></a> <FONT color="green">415</FONT> <a name="line.415"></a> <FONT color="green">416</FONT> final int dimension = in.readInt();<a name="line.416"></a> <FONT color="green">417</FONT> previousTime = in.readDouble();<a name="line.417"></a> <FONT color="green">418</FONT> currentTime = in.readDouble();<a name="line.418"></a> <FONT color="green">419</FONT> h = in.readDouble();<a name="line.419"></a> <FONT color="green">420</FONT> forward = in.readBoolean();<a name="line.420"></a> <FONT color="green">421</FONT> dirtyState = true;<a name="line.421"></a> <FONT color="green">422</FONT> <a name="line.422"></a> <FONT color="green">423</FONT> if (dimension < 0) {<a name="line.423"></a> <FONT color="green">424</FONT> currentState = null;<a name="line.424"></a> <FONT color="green">425</FONT> } else {<a name="line.425"></a> <FONT color="green">426</FONT> currentState = new double[dimension];<a name="line.426"></a> <FONT color="green">427</FONT> for (int i = 0; i < currentState.length; ++i) {<a name="line.427"></a> <FONT color="green">428</FONT> currentState[i] = in.readDouble();<a name="line.428"></a> <FONT color="green">429</FONT> }<a name="line.429"></a> <FONT color="green">430</FONT> }<a name="line.430"></a> <FONT color="green">431</FONT> <a name="line.431"></a> <FONT color="green">432</FONT> // we do NOT handle the interpolated time and state here<a name="line.432"></a> <FONT color="green">433</FONT> interpolatedTime = Double.NaN;<a name="line.433"></a> <FONT color="green">434</FONT> interpolatedState = (dimension < 0) ? null : new double[dimension];<a name="line.434"></a> <FONT color="green">435</FONT> interpolatedDerivatives = (dimension < 0) ? null : new double[dimension];<a name="line.435"></a> <FONT color="green">436</FONT> <a name="line.436"></a> <FONT color="green">437</FONT> finalized = true;<a name="line.437"></a> <FONT color="green">438</FONT> <a name="line.438"></a> <FONT color="green">439</FONT> return in.readDouble();<a name="line.439"></a> <FONT color="green">440</FONT> <a name="line.440"></a> <FONT color="green">441</FONT> }<a name="line.441"></a> <FONT color="green">442</FONT> <a name="line.442"></a> <FONT color="green">443</FONT> }<a name="line.443"></a> </PRE> </BODY> </HTML>