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* 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
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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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package org.apache.commons.math3.ode.events;
import org.apache.commons.math3.analysis.solvers.BrentSolver;
import org.apache.commons.math3.ode.FirstOrderDifferentialEquations;
import org.apache.commons.math3.ode.nonstiff.DormandPrince853Integrator;
import org.apache.commons.math3.ode.sampling.AbstractStepInterpolator;
import org.apache.commons.math3.ode.sampling.DummyStepInterpolator;
import org.junit.Assert;
import org.junit.Test;
public class EventStateTest {
// JIRA: MATH-322
@Test
public void closeEvents() {
final double r1 = 90.0;
final double r2 = 135.0;
final double gap = r2 - r1;
EventHandler closeEventsGenerator = new EventHandler() {
public void init(double t0, double[] y0, double t) {
}
public void resetState(double t, double[] y) {
}
public double g(double t, double[] y) {
return (t - r1) * (r2 - t);
}
public Action eventOccurred(double t, double[] y, boolean increasing) {
return Action.CONTINUE;
}
};
final double tolerance = 0.1;
EventState es = new EventState(closeEventsGenerator, 1.5 * gap,
tolerance, 100,
new BrentSolver(tolerance));
AbstractStepInterpolator interpolator =
new DummyStepInterpolator(new double[0], new double[0], true);
interpolator.storeTime(r1 - 2.5 * gap);
interpolator.shift();
interpolator.storeTime(r1 - 1.5 * gap);
es.reinitializeBegin(interpolator);
interpolator.shift();
interpolator.storeTime(r1 - 0.5 * gap);
Assert.assertFalse(es.evaluateStep(interpolator));
interpolator.shift();
interpolator.storeTime(0.5 * (r1 + r2));
Assert.assertTrue(es.evaluateStep(interpolator));
Assert.assertEquals(r1, es.getEventTime(), tolerance);
es.stepAccepted(es.getEventTime(), new double[0]);
interpolator.shift();
interpolator.storeTime(r2 + 0.4 * gap);
Assert.assertTrue(es.evaluateStep(interpolator));
Assert.assertEquals(r2, es.getEventTime(), tolerance);
}
// Jira: MATH-695
@Test
public void testIssue695() {
FirstOrderDifferentialEquations equation = new FirstOrderDifferentialEquations() {
public int getDimension() {
return 1;
}
public void computeDerivatives(double t, double[] y, double[] yDot) {
yDot[0] = 1.0;
}
};
DormandPrince853Integrator integrator = new DormandPrince853Integrator(0.001, 1000, 1.0e-14, 1.0e-14);
integrator.addEventHandler(new ResettingEvent(10.99), 0.1, 1.0e-9, 1000);
integrator.addEventHandler(new ResettingEvent(11.01), 0.1, 1.0e-9, 1000);
integrator.setInitialStepSize(3.0);
double target = 30.0;
double[] y = new double[1];
double tEnd = integrator.integrate(equation, 0.0, y, target, y);
Assert.assertEquals(target, tEnd, 1.0e-10);
Assert.assertEquals(32.0, y[0], 1.0e-10);
}
private static class ResettingEvent implements EventHandler {
private static double lastTriggerTime = Double.NEGATIVE_INFINITY;
private final double tEvent;
public ResettingEvent(final double tEvent) {
this.tEvent = tEvent;
}
public void init(double t0, double[] y0, double t) {
}
public double g(double t, double[] y) {
// the bug corresponding to issue 695 causes the g function
// to be called at obsolete times t despite an event
// occurring later has already been triggered.
// When this occurs, the following assertion is violated
Assert.assertTrue("going backard in time! (" + t + " < " + lastTriggerTime + ")",
t >= lastTriggerTime);
return t - tEvent;
}
public Action eventOccurred(double t, double[] y, boolean increasing) {
// remember in a class variable when the event was triggered
lastTriggerTime = t;
return Action.RESET_STATE;
}
public void resetState(double t, double[] y) {
y[0] += 1.0;
}
}
}