Commons Math example source code file (StepNormalizerTest.java)

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

Java - Commons Math tags/keywords

derivativeexception, derivativeexception, dormandprince54integrator, firstorderintegrator, fixedstephandler, fixedstephandler, integratorexception, integratorexception, override, stepnormalizer, stepnormalizertest, stepnormalizertest, testcase, testproblem3

The Commons Math StepNormalizerTest.java 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,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.math.ode.sampling;

import org.apache.commons.math.ode.DerivativeException;
import org.apache.commons.math.ode.FirstOrderIntegrator;
import org.apache.commons.math.ode.IntegratorException;
import org.apache.commons.math.ode.TestProblem3;
import org.apache.commons.math.ode.nonstiff.DormandPrince54Integrator;
import org.apache.commons.math.ode.sampling.FixedStepHandler;
import org.apache.commons.math.ode.sampling.StepNormalizer;

import junit.framework.*;

public class StepNormalizerTest
  extends TestCase {

  public StepNormalizerTest(String name) {
    super(name);
    pb    = null;
    integ = null;
  }

  public void testBoundaries()
    throws DerivativeException, IntegratorException {
    double range = pb.getFinalTime() - pb.getInitialTime();
    setLastSeen(false);
    integ.addStepHandler(new StepNormalizer(range / 10.0,
                                       new FixedStepHandler() {
                                        private static final long serialVersionUID = 1650337364641626444L;
                                        private boolean firstCall = true;
                                         public void handleStep(double t,
                                                                double[] y,
                                                                double[] yDot,
                                                                boolean isLast) {
                                           if (firstCall) {
                                             checkValue(t, pb.getInitialTime());
                                             firstCall = false;
                                           }
                                           if (isLast) {
                                             setLastSeen(true);
                                             checkValue(t, pb.getFinalTime());
                                           }
                                         }
                                       }));
    integ.integrate(pb,
                    pb.getInitialTime(), pb.getInitialState(),
                    pb.getFinalTime(), new double[pb.getDimension()]);
    assertTrue(lastSeen);
  }

  public void testBeforeEnd()
    throws DerivativeException, IntegratorException {
    final double range = pb.getFinalTime() - pb.getInitialTime();
    setLastSeen(false);
    integ.addStepHandler(new StepNormalizer(range / 10.5,
                                       new FixedStepHandler() {
                                        private static final long serialVersionUID = 2228457391561277298L;
                                        public void handleStep(double t,
                                                                double[] y,
                                                                double[] yDot,
                                                                boolean isLast) {
                                           if (isLast) {
                                             setLastSeen(true);
                                             checkValue(t,
                                                        pb.getFinalTime() - range / 21.0);
                                           }
                                         }
                                       }));
    integ.integrate(pb,
                    pb.getInitialTime(), pb.getInitialState(),
                    pb.getFinalTime(), new double[pb.getDimension()]);
    assertTrue(lastSeen);
  }

  public void checkValue(double value, double reference) {
    assertTrue(Math.abs(value - reference) < 1.0e-10);
  }

  public void setLastSeen(boolean lastSeen) {
    this.lastSeen = lastSeen;
  }

  @Override
  public void setUp() {
    pb = new TestProblem3(0.9);
    double minStep = 0;
    double maxStep = pb.getFinalTime() - pb.getInitialTime();
    integ = new DormandPrince54Integrator(minStep, maxStep, 10.e-8, 1.0e-8);
    lastSeen = false;
  }

  @Override
  public void tearDown() {
    pb    = null;
    integ = null;
  }

  TestProblem3 pb;
  FirstOrderIntegrator integ;
  boolean lastSeen;

}