001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.math.ode.sampling;
019
020 import static org.junit.Assert.assertTrue;
021
022 import java.io.ByteArrayInputStream;
023 import java.io.ByteArrayOutputStream;
024 import java.io.IOException;
025 import java.io.ObjectInputStream;
026 import java.io.ObjectOutputStream;
027 import java.util.Random;
028
029 import org.apache.commons.math.ode.ContinuousOutputModel;
030 import org.apache.commons.math.ode.DerivativeException;
031 import org.apache.commons.math.ode.IntegratorException;
032 import org.apache.commons.math.ode.TestProblem1;
033 import org.apache.commons.math.ode.TestProblem3;
034 import org.apache.commons.math.ode.nonstiff.AdamsBashforthIntegrator;
035 import org.junit.Test;
036
037 public class NordsieckStepInterpolatorTest {
038
039 @Test
040 public void derivativesConsistency()
041 throws DerivativeException, IntegratorException {
042 TestProblem3 pb = new TestProblem3();
043 AdamsBashforthIntegrator integ = new AdamsBashforthIntegrator(4, 0.0, 1.0, 1.0e-10, 1.0e-10);
044 StepInterpolatorTestUtils.checkDerivativesConsistency(integ, pb, 7e-10);
045 }
046
047 @Test
048 public void serialization()
049 throws DerivativeException, IntegratorException,
050 IOException, ClassNotFoundException {
051
052 TestProblem1 pb = new TestProblem1();
053 AdamsBashforthIntegrator integ = new AdamsBashforthIntegrator(4, 0.0, 1.0, 1.0e-10, 1.0e-10);
054 integ.addStepHandler(new ContinuousOutputModel());
055 integ.integrate(pb,
056 pb.getInitialTime(), pb.getInitialState(),
057 pb.getFinalTime(), new double[pb.getDimension()]);
058
059 ByteArrayOutputStream bos = new ByteArrayOutputStream();
060 ObjectOutputStream oos = new ObjectOutputStream(bos);
061 for (StepHandler handler : integ.getStepHandlers()) {
062 oos.writeObject(handler);
063 }
064
065 assertTrue(bos.size () > 20000);
066 assertTrue(bos.size () < 25000);
067
068 ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
069 ObjectInputStream ois = new ObjectInputStream(bis);
070 ContinuousOutputModel cm = (ContinuousOutputModel) ois.readObject();
071
072 Random random = new Random(347588535632l);
073 double maxError = 0.0;
074 for (int i = 0; i < 1000; ++i) {
075 double r = random.nextDouble();
076 double time = r * pb.getInitialTime() + (1.0 - r) * pb.getFinalTime();
077 cm.setInterpolatedTime(time);
078 double[] interpolatedY = cm.getInterpolatedState ();
079 double[] theoreticalY = pb.computeTheoreticalState(time);
080 double dx = interpolatedY[0] - theoreticalY[0];
081 double dy = interpolatedY[1] - theoreticalY[1];
082 double error = dx * dx + dy * dy;
083 if (error > maxError) {
084 maxError = error;
085 }
086 }
087
088 assertTrue(maxError < 1.0e-6);
089
090 }
091
092 }