home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (ClassicalRungeKuttaStepInterpolatorTest.java)

This example Java source code file (ClassicalRungeKuttaStepInterpolatorTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytearrayoutputstream, classicalrungekuttaintegrator, classicalrungekuttastepinterpolatortest, continuousoutputmodel, dimensionmismatchexception, ioexception, maxcountexceededexception, nobracketingexception, numberistoosmallexception, objectinputstream, objectoutputstream, random, stephandler, testproblem3, util

The ClassicalRungeKuttaStepInterpolatorTest.java Java example source code

 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *      http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.

package org.apache.commons.math3.ode.nonstiff;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Random;

import org.apache.commons.math3.exception.DimensionMismatchException;
import org.apache.commons.math3.exception.MaxCountExceededException;
import org.apache.commons.math3.exception.NoBracketingException;
import org.apache.commons.math3.exception.NumberIsTooSmallException;
import org.apache.commons.math3.ode.ContinuousOutputModel;
import org.apache.commons.math3.ode.TestProblem3;
import org.apache.commons.math3.ode.sampling.StepHandler;
import org.apache.commons.math3.ode.sampling.StepInterpolatorTestUtils;
import org.junit.Assert;
import org.junit.Test;

public class ClassicalRungeKuttaStepInterpolatorTest {

  public void derivativesConsistency()
      throws DimensionMismatchException, NumberIsTooSmallException,
             MaxCountExceededException, NoBracketingException {
    TestProblem3 pb = new TestProblem3();
    double step = (pb.getFinalTime() - pb.getInitialTime()) * 0.001;
    ClassicalRungeKuttaIntegrator integ = new ClassicalRungeKuttaIntegrator(step);
    StepInterpolatorTestUtils.checkDerivativesConsistency(integ, pb, 0.01, 6.6e-12);

  public void serialization()
    throws IOException, ClassNotFoundException,
           DimensionMismatchException, NumberIsTooSmallException,
           MaxCountExceededException, NoBracketingException  {

    TestProblem3 pb = new TestProblem3(0.9);
    double step = (pb.getFinalTime() - pb.getInitialTime()) * 0.0003;
    ClassicalRungeKuttaIntegrator integ = new ClassicalRungeKuttaIntegrator(step);
    integ.addStepHandler(new ContinuousOutputModel());
                    pb.getInitialTime(), pb.getInitialState(),
                    pb.getFinalTime(), new double[pb.getDimension()]);

    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    ObjectOutputStream    oos = new ObjectOutputStream(bos);
    for (StepHandler handler : integ.getStepHandlers()) {

    Assert.assertTrue(bos.size () > 880000);
    Assert.assertTrue(bos.size () < 900000);

    ByteArrayInputStream  bis = new ByteArrayInputStream(bos.toByteArray());
    ObjectInputStream     ois = new ObjectInputStream(bis);
    ContinuousOutputModel cm  = (ContinuousOutputModel) ois.readObject();

    Random random = new Random(347588535632l);
    double maxError = 0.0;
    for (int i = 0; i < 1000; ++i) {
      double r = random.nextDouble();
      double time = r * pb.getInitialTime() + (1.0 - r) * pb.getFinalTime();
      double[] interpolatedY = cm.getInterpolatedState ();
      double[] theoreticalY  = pb.computeTheoreticalState(time);
      double dx = interpolatedY[0] - theoreticalY[0];
      double dy = interpolatedY[1] - theoreticalY[1];
      double error = dx * dx + dy * dy;
      if (error > maxError) {
        maxError = error;

    Assert.assertTrue(maxError > 0.005);



Other Java examples (source code examples)

Here is a short list of links related to this Java ClassicalRungeKuttaStepInterpolatorTest.java source code file:

my book on functional programming


new blog posts


Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.