@Test
public void testExceedHistoryBackward() throws OrekitException, IOException {
final double period = 900.0;
// the raw detector should trigger one event at each 900s period
final DateDetector raw =
new DateDetector(orbit.getDate().shiftedBy(+0.5 * period))
.withMaxCheck(period / 3)
.withHandler(new ContinueOnEvent<DateDetector>());
for (int i = 0; i < 300; ++i) {
raw.addEventDate(orbit.getDate().shiftedBy(-(i + 0.5) * period));
}
// in fact, we will filter out half of these events, so we get only one event every 2 periods
final EventEnablingPredicateFilter<DateDetector> filtered =
new EventEnablingPredicateFilter<DateDetector>(
raw,
new EnablingPredicate<DateDetector>() {
public boolean eventIsEnabled(
SpacecraftState state, DateDetector eventDetector, double g) {
double nbPeriod = orbit.getDate().durationFrom(state.getDate()) / period;
return ((int) FastMath.floor(nbPeriod)) % 2 == 1;
}
});
Propagator propagator = new KeplerianPropagator(orbit);
EventsLogger logger = new EventsLogger();
propagator.addEventDetector(logger.monitorDetector(filtered));
propagator.propagate(orbit.getDate().shiftedBy(-301 * period));
List<LoggedEvent> events = logger.getLoggedEvents();
// 300 periods, 150 events as half of them are filtered out
Assert.assertEquals(150, events.size());
// as we have encountered a lot of enabling status changes, we exceeded the internal history
// if we try to display again the filtered g function for dates far in the future,
// we will not see the zero crossings anymore, they have been lost
propagator.clearEventsDetectors();
for (double dt = -5000.0; dt > -10000.0; dt -= 3.0) {
double filteredG = filtered.g(propagator.propagate(orbit.getDate().shiftedBy(dt)));
Assert.assertTrue(filteredG < 0.0);
}
// on the other hand, if we try to display again the filtered g function for future dates
// that are still inside the history, we still see the zero crossings
for (double dt = -195400.0; dt > -196200.0; dt -= 3.0) {
double filteredG = filtered.g(propagator.propagate(orbit.getDate().shiftedBy(dt)));
if (dt < -195750) {
Assert.assertTrue(filteredG < 0.0);
} else {
Assert.assertTrue(filteredG > 0.0);
}
}
}
@Test
public void testResetState() throws OrekitException {
final List<AbsoluteDate> reset = new ArrayList<AbsoluteDate>();
DateDetector raw =
new DateDetector(orbit.getDate().shiftedBy(3600.0))
.withMaxCheck(1000.0)
.withHandler(
new EventHandler<DateDetector>() {
public SpacecraftState resetState(
DateDetector detector, SpacecraftState oldState) {
reset.add(oldState.getDate());
return oldState;
}
public Action eventOccurred(
SpacecraftState s, DateDetector detector, boolean increasing) {
return Action.RESET_STATE;
}
});
for (int i = 2; i < 10; ++i) {
raw.addEventDate(orbit.getDate().shiftedBy(i * 3600.0));
}
EventEnablingPredicateFilter<DateDetector> filtered =
new EventEnablingPredicateFilter<DateDetector>(
raw,
new EnablingPredicate<DateDetector>() {
public boolean eventIsEnabled(
SpacecraftState state, DateDetector eventDetector, double g) {
return state.getDate().durationFrom(orbit.getDate()) > 20000.0;
}
});
Propagator propagator = new KeplerianPropagator(orbit);
EventsLogger logger = new EventsLogger();
propagator.addEventDetector(logger.monitorDetector(filtered));
propagator.propagate(orbit.getDate().shiftedBy(Constants.JULIAN_DAY));
List<LoggedEvent> events = logger.getLoggedEvents();
Assert.assertEquals(4, events.size());
Assert.assertEquals(
6 * 3600, events.get(0).getState().getDate().durationFrom(orbit.getDate()), 1.0e-6);
Assert.assertEquals(
7 * 3600, events.get(1).getState().getDate().durationFrom(orbit.getDate()), 1.0e-6);
Assert.assertEquals(
8 * 3600, events.get(2).getState().getDate().durationFrom(orbit.getDate()), 1.0e-6);
Assert.assertEquals(
9 * 3600, events.get(3).getState().getDate().durationFrom(orbit.getDate()), 1.0e-6);
Assert.assertEquals(4, reset.size());
Assert.assertEquals(6 * 3600, reset.get(0).durationFrom(orbit.getDate()), 1.0e-6);
Assert.assertEquals(7 * 3600, reset.get(1).durationFrom(orbit.getDate()), 1.0e-6);
Assert.assertEquals(8 * 3600, reset.get(2).durationFrom(orbit.getDate()), 1.0e-6);
Assert.assertEquals(9 * 3600, reset.get(3).durationFrom(orbit.getDate()), 1.0e-6);
}
