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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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package org.apache.commons.math.ode.nonstiff;
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import static org.junit.Assert.assertTrue;
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import java.io.ByteArrayInputStream;
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import java.io.ByteArrayOutputStream;
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import java.io.IOException;
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import java.io.ObjectInputStream;
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import java.io.ObjectOutputStream;
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import java.util.Random;
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import org.apache.commons.math.ode.ContinuousOutputModel;
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import org.apache.commons.math.ode.DerivativeException;
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import org.apache.commons.math.ode.IntegratorException;
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import org.apache.commons.math.ode.TestProblem3;
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import org.apache.commons.math.ode.sampling.StepHandler;
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import org.apache.commons.math.ode.sampling.StepInterpolatorTestUtils;
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import org.junit.Test;
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public class ThreeEighthesStepInterpolatorTest {
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public void derivativesConsistency()
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throws DerivativeException, IntegratorException {
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TestProblem3 pb = new TestProblem3();
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double step = (pb.getFinalTime() - pb.getInitialTime()) * 0.001;
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ThreeEighthesIntegrator integ = new ThreeEighthesIntegrator(step);
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StepInterpolatorTestUtils.checkDerivativesConsistency(integ, pb, 1.0e-10);
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public void serialization()
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throws DerivativeException, IntegratorException,
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IOException, ClassNotFoundException {
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TestProblem3 pb = new TestProblem3(0.9);
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double step = (pb.getFinalTime() - pb.getInitialTime()) * 0.0003;
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ThreeEighthesIntegrator integ = new ThreeEighthesIntegrator(step);
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integ.addStepHandler(new ContinuousOutputModel());
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pb.getInitialTime(), pb.getInitialState(),
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pb.getFinalTime(), new double[pb.getDimension()]);
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ByteArrayOutputStream bos = new ByteArrayOutputStream();
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ObjectOutputStream oos = new ObjectOutputStream(bos);
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for (StepHandler handler : integ.getStepHandlers()) {
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oos.writeObject(handler);
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assertTrue(bos.size () > 700000);
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assertTrue(bos.size () < 701000);
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ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
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ObjectInputStream ois = new ObjectInputStream(bis);
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ContinuousOutputModel cm = (ContinuousOutputModel) ois.readObject();
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Random random = new Random(347588535632l);
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double maxError = 0.0;
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for (int i = 0; i < 1000; ++i) {
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double r = random.nextDouble();
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double time = r * pb.getInitialTime() + (1.0 - r) * pb.getFinalTime();
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cm.setInterpolatedTime(time);
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double[] interpolatedY = cm.getInterpolatedState ();
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double[] theoreticalY = pb.computeTheoreticalState(time);
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double dx = interpolatedY[0] - theoreticalY[0];
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double dy = interpolatedY[1] - theoreticalY[1];
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double error = dx * dx + dy * dy;
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if (error > maxError) {
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assertTrue(maxError > 0.005);