[Boost-commit] svn:boost r71834 - sandbox/odeint/branches/karsten/libs/numeric/odeint/ideas/fusion_runge_kutta/performance/java

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] );
+    }
+
+}
\ No newline at end of file