/*
* 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.math3.ode.events;
import static org.junit.Assert.assertEquals;
import java.util.Arrays;
import org.apache.commons.math3.analysis.solvers.PegasusSolver;
import org.apache.commons.math3.ode.FirstOrderDifferentialEquations;
import org.apache.commons.math3.ode.FirstOrderIntegrator;
import org.apache.commons.math3.ode.events.EventHandler;
import org.apache.commons.math3.ode.nonstiff.DormandPrince853Integrator;
import org.apache.commons.math3.ode.nonstiff.GraggBulirschStoerIntegrator;
import org.junit.Test;
public class ReappearingEventTest {
@Test
public void testDormandPrince() {
double tEnd = test(1);
assertEquals(10.0, tEnd, 1e-7);
}
@Test
public void testGragg() {
double tEnd = test(2);
assertEquals(10.0, tEnd, 1e-7);
}
public double test(int integratorType) {
double e = 1e-15;
FirstOrderIntegrator integrator;
integrator = (integratorType == 1)
? new DormandPrince853Integrator(e, 100.0, 1e-7, 1e-7)
: new GraggBulirschStoerIntegrator(e, 100.0, 1e-7, 1e-7);
PegasusSolver rootSolver = new PegasusSolver(e, e);
integrator.addEventHandler(new Event(), 0.1, e, 1000, rootSolver);
double t0 = 6.0;
double tEnd = 10.0;
double[] y = {2.0, 2.0, 2.0, 4.0, 2.0, 7.0, 15.0};
return integrator.integrate(new Ode(), t0, y, tEnd, y);
}
private static class Ode implements FirstOrderDifferentialEquations {
public int getDimension() {
return 7;
}
public void computeDerivatives(double t, double[] y, double[] yDot) {
Arrays.fill(yDot, 1.0);
}
}
/** State events for this unit test. */
protected static class Event implements EventHandler {
public void init(double t0, double[] y0, double t) {
}
public double g(double t, double[] y) {
return y[6] - 15.0;
}
public Action eventOccurred(double t, double[] y, boolean increasing) {
return Action.STOP;
}
public void resetState(double t, double[] y) {
// Never called.
}
}
}