Subject: [Boost-commit] svn:boost r71834 - sandbox/odeint/branches/karsten/libs/numeric/odeint/ideas/fusion_runge_kutta/performance/java
From: mario.mulansky_at_[hidden]
Date: 2011-05-08 14:46:15
Author: mariomulansky
Date: 2011-05-08 14:46:15 EDT (Sun, 08 May 2011)
New Revision: 71834
URL: http://svn.boost.org/trac/boost/changeset/71834
Log:
+java apache math version
Added:
sandbox/odeint/branches/karsten/libs/numeric/odeint/ideas/fusion_runge_kutta/performance/java/
sandbox/odeint/branches/karsten/libs/numeric/odeint/ideas/fusion_runge_kutta/performance/java/rk4.java (contents, props changed)
Added: sandbox/odeint/branches/karsten/libs/numeric/odeint/ideas/fusion_runge_kutta/performance/java/rk4.java
==============================================================================
--- (empty file)
+++ sandbox/odeint/branches/karsten/libs/numeric/odeint/ideas/fusion_runge_kutta/performance/java/rk4.java 2011-05-08 14:46:15 EDT (Sun, 08 May 2011)
@@ -0,0 +1,49 @@
+//package org.apache.commons.math.ode;
+//package org.apache.commons.math.ode.nonstiff;
+
+import org.apache.commons.math.ode.FirstOrderDifferentialEquations;
+import org.apache.commons.math.ode.FirstOrderIntegrator;
+import org.apache.commons.math.ode.nonstiff.ClassicalRungeKuttaIntegrator;
+import org.apache.commons.math.ode.DerivativeException;
+import org.apache.commons.math.ode.IntegratorException;
+
+public class rk4 {
+
+
+ private static class Lorenz implements FirstOrderDifferentialEquations
+ {
+ private static double sigma = 10.0;
+ private static double R = 28.0;
+ private static double b = 8.0/3.0;
+
+ public int getDimension()
+ {
+ return 3;
+ }
+
+ public void computeDerivatives( double t , double[] y , double[] yDot )
+ {
+ yDot[0] = sigma * ( y[1] - y[0] );
+ yDot[1] = R * y[0] - y[1] - y[0] * y[2];
+ yDot[2] = y[0]*y[1] - b * y[2];
+ }
+ }
+
+
+ public static void main( String[] args )
+ {
+ double dt = 1E-10;
+ int steps = 20000000;
+ FirstOrderIntegrator rk4 = new ClassicalRungeKuttaIntegrator( dt );
+ FirstOrderDifferentialEquations ode = new Lorenz();
+ double[] y = new double[] { 0.0, 1.0 , 1.0 }; // initial state
+ try {
+ rk4.integrate(ode, 0.0, y, dt*steps , y);
+ } catch(DerivativeException de) {
+ System.out.println("wrong exception caught");
+ } catch(IntegratorException ie) {
+ }
+ System.out.println( y[0] + " " + y[1] + " " + y[2] );
+ }
+
+}
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