AbstractPropagator.java
/* Copyright 2002-2016 CS Systèmes d'Information
* Licensed to CS Systèmes d'Information (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS 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.orekit.propagation;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.orekit.attitudes.AttitudeProvider;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitMessages;
import org.orekit.errors.PropagationException;
import org.orekit.frames.Frame;
import org.orekit.propagation.events.EventDetector;
import org.orekit.propagation.sampling.OrekitFixedStepHandler;
import org.orekit.propagation.sampling.OrekitStepHandler;
import org.orekit.propagation.sampling.OrekitStepNormalizer;
import org.orekit.time.AbsoluteDate;
import org.orekit.utils.TimeStampedPVCoordinates;
/** Common handling of {@link Propagator} methods for analytical propagators.
* <p>
* This abstract class allows to provide easily the full set of {@link Propagator}
* methods, including all propagation modes support and discrete events support for
* any simple propagation method.
* </p>
* @author Luc Maisonobe
*/
public abstract class AbstractPropagator implements Propagator {
/** Propagation mode. */
private int mode;
/** Fixed step size. */
private double fixedStepSize;
/** Step handler. */
private OrekitStepHandler stepHandler;
/** Start date. */
private AbsoluteDate startDate;
/** Attitude provider. */
private AttitudeProvider attitudeProvider;
/** Additional state providers. */
private final List<AdditionalStateProvider> additionalStateProviders;
/** Initial state. */
private SpacecraftState initialState;
/** Build a new instance.
*/
protected AbstractPropagator() {
mode = SLAVE_MODE;
stepHandler = null;
fixedStepSize = Double.NaN;
additionalStateProviders = new ArrayList<AdditionalStateProvider>();
}
/** Set a start date.
* @param startDate start date
*/
protected void setStartDate(final AbsoluteDate startDate) {
this.startDate = startDate;
}
/** Get the start date.
* @return start date
*/
protected AbsoluteDate getStartDate() {
return startDate;
}
/** {@inheritDoc} */
public AttitudeProvider getAttitudeProvider() {
return attitudeProvider;
}
/** {@inheritDoc} */
public void setAttitudeProvider(final AttitudeProvider attitudeProvider) {
this.attitudeProvider = attitudeProvider;
}
/** {@inheritDoc} */
public SpacecraftState getInitialState() throws PropagationException {
return initialState;
}
/** {@inheritDoc} */
public int getMode() {
return mode;
}
/** {@inheritDoc} */
public Frame getFrame() {
return initialState.getFrame();
}
/** {@inheritDoc} */
public void resetInitialState(final SpacecraftState state) throws PropagationException {
initialState = state;
setStartDate(state.getDate());
}
/** {@inheritDoc} */
public void setSlaveMode() {
mode = SLAVE_MODE;
stepHandler = null;
fixedStepSize = Double.NaN;
}
/** {@inheritDoc} */
public void setMasterMode(final double h,
final OrekitFixedStepHandler handler) {
setMasterMode(new OrekitStepNormalizer(h, handler));
fixedStepSize = h;
}
/** {@inheritDoc} */
public void setMasterMode(final OrekitStepHandler handler) {
mode = MASTER_MODE;
stepHandler = handler;
fixedStepSize = Double.NaN;
}
/** {@inheritDoc} */
public void setEphemerisMode() {
mode = EPHEMERIS_GENERATION_MODE;
stepHandler = null;
fixedStepSize = Double.NaN;
}
/** {@inheritDoc} */
public void addAdditionalStateProvider(final AdditionalStateProvider additionalStateProvider)
throws OrekitException {
// check if the name is already used
if (isAdditionalStateManaged(additionalStateProvider.getName())) {
// this additional state is already registered, complain
throw new OrekitException(OrekitMessages.ADDITIONAL_STATE_NAME_ALREADY_IN_USE,
additionalStateProvider.getName());
}
// this is really a new name, add it
additionalStateProviders.add(additionalStateProvider);
}
/** {@inheritDoc} */
public List<AdditionalStateProvider> getAdditionalStateProviders() {
return Collections.unmodifiableList(additionalStateProviders);
}
/** Update state by adding all additional states.
* @param original original state
* @return updated state, with all additional states included
* @exception PropagationException if one of the providers throws one
* @see #addAdditionalStateProvider(AdditionalStateProvider)
*/
protected SpacecraftState updateAdditionalStates(final SpacecraftState original)
throws PropagationException {
// start with original state,
// which may already contain additional states, for example in interpolated ephemerides
SpacecraftState updated = original;
if (initialState != null) {
// there is an initial state
// (null initial states occur for example in interpolated ephemerides)
// copy the additional states present in initialState but otherwise not managed
for (final Map.Entry<String, double[]> initial : initialState.getAdditionalStates().entrySet()) {
if (!isAdditionalStateManaged(initial.getKey())) {
// this additional state was in the initial state, but is unknown to the propagator
// we simply copy its initial value as is
updated = updated.addAdditionalState(initial.getKey(), initial.getValue());
}
}
}
// update the additional states managed by providers
for (final AdditionalStateProvider provider : additionalStateProviders) {
updated = updated.addAdditionalState(provider.getName(),
provider.getAdditionalState(updated));
}
return updated;
}
/** {@inheritDoc} */
public boolean isAdditionalStateManaged(final String name) {
for (final AdditionalStateProvider provider : additionalStateProviders) {
if (provider.getName().equals(name)) {
return true;
}
}
return false;
}
/** {@inheritDoc} */
public String[] getManagedAdditionalStates() {
final String[] managed = new String[additionalStateProviders.size()];
for (int i = 0; i < managed.length; ++i) {
managed[i] = additionalStateProviders.get(i).getName();
}
return managed;
}
/** Get the fixed step size.
* @return fixed step size (or NaN if there are no fixed step size).
*/
protected double getFixedStepSize() {
return fixedStepSize;
}
/** Get the step handler.
* @return step handler
*/
protected OrekitStepHandler getStepHandler() {
return stepHandler;
}
/** {@inheritDoc} */
public abstract BoundedPropagator getGeneratedEphemeris();
/** {@inheritDoc} */
public abstract <T extends EventDetector> void addEventDetector(final T detector);
/** {@inheritDoc} */
public abstract Collection<EventDetector> getEventsDetectors();
/** {@inheritDoc} */
public abstract void clearEventsDetectors();
/** {@inheritDoc} */
public SpacecraftState propagate(final AbsoluteDate target) throws PropagationException {
if (startDate == null) {
startDate = getInitialState().getDate();
}
return propagate(startDate, target);
}
/** {@inheritDoc} */
public TimeStampedPVCoordinates getPVCoordinates(final AbsoluteDate date, final Frame frame)
throws OrekitException {
return propagate(date).getPVCoordinates(frame);
}
}