FieldAbstractIntegratedPropagator.java
/* Copyright 2002-2024 CS GROUP
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* 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
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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.orekit.propagation.integration;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.Field;
import org.hipparchus.analysis.solvers.FieldBracketingNthOrderBrentSolver;
import org.hipparchus.exception.MathIllegalArgumentException;
import org.hipparchus.exception.MathIllegalStateException;
import org.hipparchus.ode.FieldDenseOutputModel;
import org.hipparchus.ode.FieldExpandableODE;
import org.hipparchus.ode.FieldODEIntegrator;
import org.hipparchus.ode.FieldODEState;
import org.hipparchus.ode.FieldODEStateAndDerivative;
import org.hipparchus.ode.FieldOrdinaryDifferentialEquation;
import org.hipparchus.ode.FieldSecondaryODE;
import org.hipparchus.ode.events.Action;
import org.hipparchus.ode.events.FieldAdaptableInterval;
import org.hipparchus.ode.events.FieldODEEventDetector;
import org.hipparchus.ode.events.FieldODEEventHandler;
import org.hipparchus.ode.sampling.AbstractFieldODEStateInterpolator;
import org.hipparchus.ode.sampling.FieldODEStateInterpolator;
import org.hipparchus.ode.sampling.FieldODEStepHandler;
import org.hipparchus.util.MathArrays;
import org.hipparchus.util.Precision;
import org.orekit.attitudes.AttitudeProvider;
import org.orekit.errors.OrekitException;
import org.orekit.errors.OrekitInternalError;
import org.orekit.errors.OrekitMessages;
import org.orekit.frames.Frame;
import org.orekit.orbits.OrbitType;
import org.orekit.orbits.PositionAngleType;
import org.orekit.propagation.FieldAbstractPropagator;
import org.orekit.propagation.FieldBoundedPropagator;
import org.orekit.propagation.FieldEphemerisGenerator;
import org.orekit.propagation.FieldSpacecraftState;
import org.orekit.propagation.PropagationType;
import org.orekit.propagation.events.FieldEventDetector;
import org.orekit.propagation.events.handlers.FieldEventHandler;
import org.orekit.propagation.sampling.FieldOrekitStepHandler;
import org.orekit.propagation.sampling.FieldOrekitStepInterpolator;
import org.orekit.time.FieldAbsoluteDate;
import org.orekit.utils.FieldArrayDictionary;
/** Common handling of {@link org.orekit.propagation.FieldPropagator FieldPropagator}
* methods for both numerical and semi-analytical propagators.
* @author Luc Maisonobe
* @param <T> type of the field element
*/
public abstract class FieldAbstractIntegratedPropagator<T extends CalculusFieldElement<T>> extends FieldAbstractPropagator<T> {
/** Internal name used for complete secondary state dimension.
* @since 11.1
*/
private static final String SECONDARY_DIMENSION = "Orekit-secondary-dimension";
/** Event detectors not related to force models. */
private final List<FieldEventDetector<T>> detectors;
/** Step handlers dedicated to ephemeris generation. */
private final List<FieldStoringStepHandler> ephemerisGenerators;
/** Integrator selected by the user for the orbital extrapolation process. */
private final FieldODEIntegrator<T> integrator;
/** Offsets of secondary states managed by {@link FieldAdditionalDerivativesProvider}.
* @since 11.1
*/
private final Map<String, Integer> secondaryOffsets;
/** Additional derivatives providers.
* @since 11.1
*/
private final List<FieldAdditionalDerivativesProvider<T>> additionalDerivativesProviders;
/** Counter for differential equations calls. */
private int calls;
/** Mapper between raw double components and space flight dynamics objects. */
private FieldStateMapper<T> stateMapper;
/**
* Attitude provider when evaluating derivatives. Can be a frozen one for performance.
* @since 12.1
*/
private AttitudeProvider attitudeProviderForDerivatives;
/** Flag for resetting the state at end of propagation. */
private boolean resetAtEnd;
/** Type of orbit to output (mean or osculating) <br/>
* <p>
* This is used only in the case of semi-analytical propagators where there is a clear separation between
* mean and short periodic elements. It is ignored by the Numerical propagator.
* </p>
*/
private final PropagationType propagationType;
/** Build a new instance.
* @param integrator numerical integrator to use for propagation.
* @param propagationType type of orbit to output (mean or osculating).
* @param field Field used by default
*/
protected FieldAbstractIntegratedPropagator(final Field<T> field, final FieldODEIntegrator<T> integrator, final PropagationType propagationType) {
super(field);
detectors = new ArrayList<>();
ephemerisGenerators = new ArrayList<>();
additionalDerivativesProviders = new ArrayList<>();
this.secondaryOffsets = new HashMap<>();
this.integrator = integrator;
this.propagationType = propagationType;
this.resetAtEnd = true;
}
/** Allow/disallow resetting the initial state at end of propagation.
* <p>
* By default, at the end of the propagation, the propagator resets the initial state
* to the final state, thus allowing a new propagation to be started from there without
* recomputing the part already performed. Calling this method with {@code resetAtEnd} set
* to false changes prevents such reset.
* </p>
* @param resetAtEnd if true, at end of each propagation, the {@link
* #getInitialState() initial state} will be reset to the final state of
* the propagation, otherwise the initial state will be preserved
* @since 9.0
*/
public void setResetAtEnd(final boolean resetAtEnd) {
this.resetAtEnd = resetAtEnd;
}
/** Getter for the resetting flag regarding initial state.
* @return resetting flag
* @since 12.0
*/
public boolean getResetAtEnd() {
return this.resetAtEnd;
}
/**
* Method called when initializing the attitude provider used when evaluating derivatives.
* @return attitude provider for derivatives
*/
protected AttitudeProvider initializeAttitudeProviderForDerivatives() {
return getAttitudeProvider();
}
/** Initialize the mapper.
* @param field Field used by default
*/
protected void initMapper(final Field<T> field) {
final T zero = field.getZero();
stateMapper = createMapper(null, zero.add(Double.NaN), null, null, null, null);
}
/** Get the integrator's name.
* @return name of underlying integrator
* @since 12.0
*/
public String getIntegratorName() {
return integrator.getName();
}
/** {@inheritDoc} */
@Override
public void setAttitudeProvider(final AttitudeProvider attitudeProvider) {
super.setAttitudeProvider(attitudeProvider);
stateMapper = createMapper(stateMapper.getReferenceDate(), stateMapper.getMu(),
stateMapper.getOrbitType(), stateMapper.getPositionAngleType(),
attitudeProvider, stateMapper.getFrame());
}
/** Set propagation orbit type.
* @param orbitType orbit type to use for propagation
*/
protected void setOrbitType(final OrbitType orbitType) {
stateMapper = createMapper(stateMapper.getReferenceDate(), stateMapper.getMu(),
orbitType, stateMapper.getPositionAngleType(),
stateMapper.getAttitudeProvider(), stateMapper.getFrame());
}
/** Get propagation parameter type.
* @return orbit type used for propagation
*/
protected OrbitType getOrbitType() {
return stateMapper.getOrbitType();
}
/** Check if only the mean elements should be used in a semi-analytical propagation.
* @return {@link PropagationType MEAN} if only mean elements have to be used or
* {@link PropagationType OSCULATING} if osculating elements have to be also used.
*/
protected PropagationType isMeanOrbit() {
return propagationType;
}
/** Get the propagation type.
* @return propagation type.
* @since 11.3.2
*/
public PropagationType getPropagationType() {
return propagationType;
}
/** Set position angle type.
* <p>
* The position parameter type is meaningful only if {@link
* #getOrbitType() propagation orbit type}
* support it. As an example, it is not meaningful for propagation
* in {@link OrbitType#CARTESIAN Cartesian} parameters.
* </p>
* @param positionAngleType angle type to use for propagation
*/
protected void setPositionAngleType(final PositionAngleType positionAngleType) {
stateMapper = createMapper(stateMapper.getReferenceDate(), stateMapper.getMu(),
stateMapper.getOrbitType(), positionAngleType,
stateMapper.getAttitudeProvider(), stateMapper.getFrame());
}
/** Get propagation parameter type.
* @return angle type to use for propagation
*/
protected PositionAngleType getPositionAngleType() {
return stateMapper.getPositionAngleType();
}
/** Set the central attraction coefficient μ.
* @param mu central attraction coefficient (m³/s²)
*/
public void setMu(final T mu) {
stateMapper = createMapper(stateMapper.getReferenceDate(), mu,
stateMapper.getOrbitType(), stateMapper.getPositionAngleType(),
stateMapper.getAttitudeProvider(), stateMapper.getFrame());
}
/** Get the central attraction coefficient μ.
* @return mu central attraction coefficient (m³/s²)
* @see #setMu(CalculusFieldElement)
*/
public T getMu() {
return stateMapper.getMu();
}
/** Get the number of calls to the differential equations computation method.
* <p>The number of calls is reset each time the {@link #propagate(FieldAbsoluteDate)}
* method is called.</p>
* @return number of calls to the differential equations computation method
*/
public int getCalls() {
return calls;
}
/** {@inheritDoc} */
@Override
public boolean isAdditionalStateManaged(final String name) {
// first look at already integrated states
if (super.isAdditionalStateManaged(name)) {
return true;
}
// then look at states we integrate ourselves
for (final FieldAdditionalDerivativesProvider<T> provider : additionalDerivativesProviders) {
if (provider.getName().equals(name)) {
return true;
}
}
return false;
}
/** {@inheritDoc} */
@Override
public String[] getManagedAdditionalStates() {
final String[] alreadyIntegrated = super.getManagedAdditionalStates();
final String[] managed = new String[alreadyIntegrated.length + additionalDerivativesProviders.size()];
System.arraycopy(alreadyIntegrated, 0, managed, 0, alreadyIntegrated.length);
for (int i = 0; i < additionalDerivativesProviders.size(); ++i) {
managed[i + alreadyIntegrated.length] = additionalDerivativesProviders.get(i).getName();
}
return managed;
}
/** Add a provider for user-specified state derivatives to be integrated along with the orbit propagation.
* @param provider provider for additional derivatives
* @see #addAdditionalStateProvider(org.orekit.propagation.FieldAdditionalStateProvider)
* @since 11.1
*/
public void addAdditionalDerivativesProvider(final FieldAdditionalDerivativesProvider<T> provider) {
// check if the name is already used
if (isAdditionalStateManaged(provider.getName())) {
// these derivatives are already registered, complain
throw new OrekitException(OrekitMessages.ADDITIONAL_STATE_NAME_ALREADY_IN_USE,
provider.getName());
}
// this is really a new set of derivatives, add it
additionalDerivativesProviders.add(provider);
secondaryOffsets.clear();
}
/** Get an unmodifiable list of providers for additional derivatives.
* @return providers for additional derivatives
* @since 11.1
*/
public List<FieldAdditionalDerivativesProvider<T>> getAdditionalDerivativesProviders() {
return Collections.unmodifiableList(additionalDerivativesProviders);
}
/** {@inheritDoc} */
public <D extends FieldEventDetector<T>> void addEventDetector(final D detector) {
detectors.add(detector);
}
/** {@inheritDoc} */
public Collection<FieldEventDetector<T>> getEventDetectors() {
return Collections.unmodifiableCollection(detectors);
}
/** {@inheritDoc} */
public void clearEventsDetectors() {
detectors.clear();
}
/** Set up all user defined event detectors.
*/
protected void setUpUserEventDetectors() {
for (final FieldEventDetector<T> detector : detectors) {
setUpEventDetector(integrator, detector);
}
}
/** Wrap an Orekit event detector and register it to the integrator.
* @param integ integrator into which event detector should be registered
* @param detector event detector to wrap
*/
protected void setUpEventDetector(final FieldODEIntegrator<T> integ, final FieldEventDetector<T> detector) {
integ.addEventDetector(new FieldAdaptedEventDetector(detector));
}
/** {@inheritDoc} */
@Override
public FieldEphemerisGenerator<T> getEphemerisGenerator() {
final FieldStoringStepHandler storingHandler = new FieldStoringStepHandler();
ephemerisGenerators.add(storingHandler);
return storingHandler;
}
/** Create a mapper between raw double components and spacecraft state.
/** Simple constructor.
* <p>
* The position parameter type is meaningful only if {@link
* #getOrbitType() propagation orbit type}
* support it. As an example, it is not meaningful for propagation
* in {@link OrbitType#CARTESIAN Cartesian} parameters.
* </p>
* @param referenceDate reference date
* @param mu central attraction coefficient (m³/s²)
* @param orbitType orbit type to use for mapping
* @param positionAngleType angle type to use for propagation
* @param attitudeProvider attitude provider
* @param frame inertial frame
* @return new mapper
*/
protected abstract FieldStateMapper<T> createMapper(FieldAbsoluteDate<T> referenceDate, T mu,
OrbitType orbitType, PositionAngleType positionAngleType,
AttitudeProvider attitudeProvider, Frame frame);
/** Get the differential equations to integrate (for main state only).
* @param integ numerical integrator to use for propagation.
* @return differential equations for main state
*/
protected abstract MainStateEquations<T> getMainStateEquations(FieldODEIntegrator<T> integ);
/** {@inheritDoc} */
@Override
public FieldSpacecraftState<T> propagate(final FieldAbsoluteDate<T> target) {
if (getStartDate() == null) {
if (getInitialState() == null) {
throw new OrekitException(OrekitMessages.INITIAL_STATE_NOT_SPECIFIED_FOR_ORBIT_PROPAGATION);
}
setStartDate(getInitialState().getDate());
}
return propagate(getStartDate(), target);
}
/** {@inheritDoc} */
public FieldSpacecraftState<T> propagate(final FieldAbsoluteDate<T> tStart, final FieldAbsoluteDate<T> tEnd) {
if (getInitialState() == null) {
throw new OrekitException(OrekitMessages.INITIAL_STATE_NOT_SPECIFIED_FOR_ORBIT_PROPAGATION);
}
// make sure the integrator will be reset properly even if we change its events handlers and step handlers
try (IntegratorResetter<T> resetter = new IntegratorResetter<>(integrator)) {
// Initialize additional states
initializeAdditionalStates(tEnd);
if (!tStart.equals(getInitialState().getDate())) {
// if propagation start date is not initial date,
// propagate from initial to start date without event detection
try (IntegratorResetter<T> startResetter = new IntegratorResetter<>(integrator)) {
integrateDynamics(tStart);
}
}
// set up events added by user
setUpUserEventDetectors();
// set up step handlers
for (final FieldOrekitStepHandler<T> handler : getMultiplexer().getHandlers()) {
integrator.addStepHandler(new FieldAdaptedStepHandler(handler));
}
for (final FieldStoringStepHandler generator : ephemerisGenerators) {
generator.setEndDate(tEnd);
integrator.addStepHandler(generator);
}
// propagate from start date to end date with event detection
final FieldSpacecraftState<T> state = integrateDynamics(tEnd);
// Finalize event detectors
getEventDetectors().forEach(detector -> detector.finish(state));
return state;
}
}
/** Reset initial state with a given propagation type.
*
* <p> By default this method returns the same as method resetInitialState(FieldSpacecraftState)
* <p> Its purpose is mostly to be derived in FieldDSSTPropagator
*
* @param state new initial state to consider
* @param stateType type of the new state (mean or osculating)
* @since 12.1.3
*/
public void resetInitialState(final FieldSpacecraftState<T> state, final PropagationType stateType) {
// Default behavior, do not take propagation type into account
resetInitialState(state);
}
/** Propagation with or without event detection.
* @param tEnd target date to which orbit should be propagated
* @return state at end of propagation
*/
private FieldSpacecraftState<T> integrateDynamics(final FieldAbsoluteDate<T> tEnd) {
try {
initializePropagation();
if (getInitialState().getDate().equals(tEnd)) {
// don't extrapolate
return getInitialState();
}
// space dynamics view
stateMapper = createMapper(getInitialState().getDate(), stateMapper.getMu(),
stateMapper.getOrbitType(), stateMapper.getPositionAngleType(),
stateMapper.getAttitudeProvider(), getInitialState().getFrame());
// set propagation orbit type
if (Double.isNaN(getMu().getReal())) {
setMu(getInitialState().getMu());
}
if (getInitialState().getMass().getReal() <= 0.0) {
throw new OrekitException(OrekitMessages.NOT_POSITIVE_SPACECRAFT_MASS,
getInitialState().getMass());
}
// convert space flight dynamics API to math API
final FieldSpacecraftState<T> initialIntegrationState = getInitialIntegrationState();
final FieldODEState<T> mathInitialState = createInitialState(initialIntegrationState);
final FieldExpandableODE<T> mathODE = createODE(integrator);
// mathematical integration
final FieldODEStateAndDerivative<T> mathFinalState;
beforeIntegration(initialIntegrationState, tEnd);
mathFinalState = integrator.integrate(mathODE, mathInitialState,
tEnd.durationFrom(getInitialState().getDate()));
afterIntegration();
// get final state
FieldSpacecraftState<T> finalState =
stateMapper.mapArrayToState(stateMapper.mapDoubleToDate(mathFinalState.getTime(), tEnd),
mathFinalState.getPrimaryState(),
mathFinalState.getPrimaryDerivative(),
propagationType);
finalState = updateAdditionalStatesAndDerivatives(finalState, mathFinalState);
if (resetAtEnd) {
resetInitialState(finalState, propagationType);
setStartDate(finalState.getDate());
}
return finalState;
} catch (OrekitException pe) {
throw pe;
} catch (MathIllegalArgumentException | MathIllegalStateException me) {
throw OrekitException.unwrap(me);
}
}
/**
* Returns an updated version of the inputted state with additional states, including
* from derivatives providers.
* @param originalState input state
* @param os ODE state and derivative
* @return new state
* @since 12.1
*/
private FieldSpacecraftState<T> updateAdditionalStatesAndDerivatives(final FieldSpacecraftState<T> originalState,
final FieldODEStateAndDerivative<T> os) {
FieldSpacecraftState<T> updatedState = originalState;
if (os.getNumberOfSecondaryStates() > 0) {
final T[] secondary = os.getSecondaryState(1);
final T[] secondaryDerivative = os.getSecondaryDerivative(1);
for (final FieldAdditionalDerivativesProvider<T> provider : additionalDerivativesProviders) {
final String name = provider.getName();
final int offset = secondaryOffsets.get(name);
final int dimension = provider.getDimension();
updatedState = updatedState.addAdditionalState(name, Arrays.copyOfRange(secondary, offset, offset + dimension));
updatedState = updatedState.addAdditionalStateDerivative(name, Arrays.copyOfRange(secondaryDerivative, offset, offset + dimension));
}
}
return updateAdditionalStates(updatedState);
}
/** Get the initial state for integration.
* @return initial state for integration
*/
protected FieldSpacecraftState<T> getInitialIntegrationState() {
return getInitialState();
}
/** Create an initial state.
* @param initialState initial state in flight dynamics world
* @return initial state in mathematics world
*/
private FieldODEState<T> createInitialState(final FieldSpacecraftState<T> initialState) {
// retrieve initial state
final T[] primary = MathArrays.buildArray(initialState.getA().getField(), getBasicDimension());
stateMapper.mapStateToArray(initialState, primary, null);
if (secondaryOffsets.isEmpty()) {
// compute dimension of the secondary state
int offset = 0;
for (final FieldAdditionalDerivativesProvider<T> provider : additionalDerivativesProviders) {
secondaryOffsets.put(provider.getName(), offset);
offset += provider.getDimension();
}
secondaryOffsets.put(SECONDARY_DIMENSION, offset);
}
return new FieldODEState<>(initialState.getA().getField().getZero(), primary, secondary(initialState));
}
/** Create secondary state.
* @param state spacecraft state
* @return secondary state
* @since 11.1
*/
private T[][] secondary(final FieldSpacecraftState<T> state) {
if (secondaryOffsets.isEmpty()) {
return null;
}
final T[][] secondary = MathArrays.buildArray(state.getDate().getField(), 1, secondaryOffsets.get(SECONDARY_DIMENSION));
for (final FieldAdditionalDerivativesProvider<T> provider : additionalDerivativesProviders) {
final String name = provider.getName();
final int offset = secondaryOffsets.get(name);
final T[] additional = state.getAdditionalState(name);
System.arraycopy(additional, 0, secondary[0], offset, additional.length);
}
return secondary;
}
/** Create secondary state derivative.
* @param state spacecraft state
* @return secondary state derivative
* @since 11.1
*/
private T[][] secondaryDerivative(final FieldSpacecraftState<T> state) {
if (secondaryOffsets.isEmpty()) {
return null;
}
final T[][] secondaryDerivative = MathArrays.buildArray(state.getDate().getField(), 1, secondaryOffsets.get(SECONDARY_DIMENSION));
for (final FieldAdditionalDerivativesProvider<T> providcer : additionalDerivativesProviders) {
final String name = providcer.getName();
final int offset = secondaryOffsets.get(name);
final T[] additionalDerivative = state.getAdditionalStateDerivative(name);
System.arraycopy(additionalDerivative, 0, secondaryDerivative[0], offset, additionalDerivative.length);
}
return secondaryDerivative;
}
/** Create an ODE with all equations.
* @param integ numerical integrator to use for propagation.
* @return a new ode
*/
private FieldExpandableODE<T> createODE(final FieldODEIntegrator<T> integ) {
final FieldExpandableODE<T> ode =
new FieldExpandableODE<>(new ConvertedMainStateEquations(getMainStateEquations(integ)));
// secondary part of the ODE
if (!additionalDerivativesProviders.isEmpty()) {
ode.addSecondaryEquations(new ConvertedSecondaryStateEquations());
}
return ode;
}
/** Method called just before integration.
* <p>
* The default implementation does nothing, it may be specialized in subclasses.
* </p>
* @param initialState initial state
* @param tEnd target date at which state should be propagated
*/
protected void beforeIntegration(final FieldSpacecraftState<T> initialState,
final FieldAbsoluteDate<T> tEnd) {
// do nothing by default
}
/** Method called just after integration.
* <p>
* The default implementation does nothing, it may be specialized in subclasses.
* </p>
*/
protected void afterIntegration() {
// do nothing by default
}
/** Get state vector dimension without additional parameters.
* @return state vector dimension without additional parameters.
*/
public int getBasicDimension() {
return 7;
}
/** Get the integrator used by the propagator.
* @return the integrator.
*/
protected FieldODEIntegrator<T> getIntegrator() {
return integrator;
}
/** Convert a state from mathematical world to space flight dynamics world.
* @param os mathematical state
* @return space flight dynamics state
*/
private FieldSpacecraftState<T> convert(final FieldODEStateAndDerivative<T> os) {
FieldSpacecraftState<T> s =
stateMapper.mapArrayToState(os.getTime(),
os.getPrimaryState(),
os.getPrimaryDerivative(),
propagationType);
if (os.getNumberOfSecondaryStates() > 0) {
final T[] secondary = os.getSecondaryState(1);
final T[] secondaryDerivative = os.getSecondaryDerivative(1);
for (final FieldAdditionalDerivativesProvider<T> equations : additionalDerivativesProviders) {
final String name = equations.getName();
final int offset = secondaryOffsets.get(name);
final int dimension = equations.getDimension();
s = s.addAdditionalState(name, Arrays.copyOfRange(secondary, offset, offset + dimension));
s = s.addAdditionalStateDerivative(name, Arrays.copyOfRange(secondaryDerivative, offset, offset + dimension));
}
}
s = updateAdditionalStates(s);
return s;
}
/** Convert a state from space flight dynamics world to mathematical world.
* @param state space flight dynamics state
* @return mathematical state
*/
private FieldODEStateAndDerivative<T> convert(final FieldSpacecraftState<T> state) {
// retrieve initial state
final T[] primary = MathArrays.buildArray(getField(), getBasicDimension());
final T[] primaryDot = MathArrays.buildArray(getField(), getBasicDimension());
stateMapper.mapStateToArray(state, primary, primaryDot);
// secondary part of the ODE
final T[][] secondary = secondary(state);
final T[][] secondaryDerivative = secondaryDerivative(state);
return new FieldODEStateAndDerivative<>(stateMapper.mapDateToDouble(state.getDate()),
primary, primaryDot,
secondary, secondaryDerivative);
}
/** Differential equations for the main state (orbit, attitude and mass).
* @param <T> type of the field element
*/
public interface MainStateEquations<T extends CalculusFieldElement<T>> {
/**
* Initialize the equations at the start of propagation. This method will be
* called before any calls to {@link #computeDerivatives(FieldSpacecraftState)}.
*
* <p> The default implementation of this method does nothing.
*
* @param initialState initial state information at the start of propagation.
* @param target date of propagation. Not equal to {@code
* initialState.getDate()}.
*/
void init(FieldSpacecraftState<T> initialState, FieldAbsoluteDate<T> target);
/** Compute differential equations for main state.
* @param state current state
* @return derivatives of main state
*/
T[] computeDerivatives(FieldSpacecraftState<T> state);
}
/** Differential equations for the main state (orbit, attitude and mass), with converted API. */
private class ConvertedMainStateEquations implements FieldOrdinaryDifferentialEquation<T> {
/** Main state equations. */
private final MainStateEquations<T> main;
/** Simple constructor.
* @param main main state equations
*/
ConvertedMainStateEquations(final MainStateEquations<T> main) {
this.main = main;
calls = 0;
}
/** {@inheritDoc} */
public int getDimension() {
return getBasicDimension();
}
@Override
public void init(final T t0, final T[] y0, final T finalTime) {
// update space dynamics view
FieldSpacecraftState<T> initialState = stateMapper.mapArrayToState(t0, y0, null, PropagationType.MEAN);
initialState = updateAdditionalStates(initialState);
initialState = updateStatesFromAdditionalDerivativesIfKnown(initialState);
final FieldAbsoluteDate<T> target = stateMapper.mapDoubleToDate(finalTime);
main.init(initialState, target);
attitudeProviderForDerivatives = initializeAttitudeProviderForDerivatives();
}
/**
* Returns an updated version of the inputted state, with additional states from
* derivatives providers as given in the stored initial state.
* @param originalState input state
* @return new state
* @since 12.1
*/
private FieldSpacecraftState<T> updateStatesFromAdditionalDerivativesIfKnown(final FieldSpacecraftState<T> originalState) {
FieldSpacecraftState<T> updatedState = originalState;
final FieldSpacecraftState<T> storedInitialState = getInitialState();
final T originalTime = stateMapper.mapDateToDouble(originalState.getDate());
if (storedInitialState != null && stateMapper.mapDateToDouble(storedInitialState.getDate()).subtract(originalTime).isZero()) {
for (final FieldAdditionalDerivativesProvider<T> provider: additionalDerivativesProviders) {
final String name = provider.getName();
final T[] value = storedInitialState.getAdditionalState(name);
updatedState = updatedState.addAdditionalState(name, value);
}
}
return updatedState;
}
/** {@inheritDoc} */
public T[] computeDerivatives(final T t, final T[] y) {
// increment calls counter
++calls;
// update space dynamics view
stateMapper.setAttitudeProvider(attitudeProviderForDerivatives);
FieldSpacecraftState<T> currentState = stateMapper.mapArrayToState(t, y, null, PropagationType.MEAN);
stateMapper.setAttitudeProvider(getAttitudeProvider());
currentState = updateAdditionalStates(currentState);
// compute main state differentials
return main.computeDerivatives(currentState);
}
}
/** Differential equations for the secondary state (Jacobians, user variables ...), with converted API. */
private class ConvertedSecondaryStateEquations implements FieldSecondaryODE<T> {
/** Dimension of the combined additional states. */
private final int combinedDimension;
/** Simple constructor.
*/
ConvertedSecondaryStateEquations() {
this.combinedDimension = secondaryOffsets.get(SECONDARY_DIMENSION);
}
/** {@inheritDoc} */
@Override
public int getDimension() {
return combinedDimension;
}
/** {@inheritDoc} */
@Override
public void init(final T t0, final T[] primary0,
final T[] secondary0, final T finalTime) {
// update space dynamics view
final FieldSpacecraftState<T> initialState = convert(t0, primary0, null, secondary0);
final FieldAbsoluteDate<T> target = stateMapper.mapDoubleToDate(finalTime);
for (final FieldAdditionalDerivativesProvider<T> provider : additionalDerivativesProviders) {
provider.init(initialState, target);
}
}
/** {@inheritDoc} */
@Override
public T[] computeDerivatives(final T t, final T[] primary,
final T[] primaryDot, final T[] secondary) {
// update space dynamics view
// the integrable generators generate method will be called here,
// according to the generators yield order
FieldSpacecraftState<T> updated = convert(t, primary, primaryDot, secondary);
// set up queue for equations
final Queue<FieldAdditionalDerivativesProvider<T>> pending = new LinkedList<>(additionalDerivativesProviders);
// gather the derivatives from all additional equations, taking care of dependencies
final T[] secondaryDot = MathArrays.buildArray(t.getField(), combinedDimension);
int yieldCount = 0;
while (!pending.isEmpty()) {
final FieldAdditionalDerivativesProvider<T> equations = pending.remove();
if (equations.yields(updated)) {
// these equations have to wait for another set,
// we put them again in the pending queue
pending.add(equations);
if (++yieldCount >= pending.size()) {
// all pending equations yielded!, they probably need data not yet initialized
// we let the propagation proceed, if these data are really needed right now
// an appropriate exception will be triggered when caller tries to access them
break;
}
} else {
// we can use these equations right now
final String name = equations.getName();
final int offset = secondaryOffsets.get(name);
final int dimension = equations.getDimension();
final FieldCombinedDerivatives<T> derivatives = equations.combinedDerivatives(updated);
final T[] additionalPart = derivatives.getAdditionalDerivatives();
final T[] mainPart = derivatives.getMainStateDerivativesIncrements();
System.arraycopy(additionalPart, 0, secondaryDot, offset, dimension);
updated = updated.addAdditionalStateDerivative(name, additionalPart);
if (mainPart != null) {
// this equation does change the main state derivatives
for (int i = 0; i < mainPart.length; ++i) {
primaryDot[i] = primaryDot[i].add(mainPart[i]);
}
}
yieldCount = 0;
}
}
return secondaryDot;
}
/** Convert mathematical view to space view.
* @param t current value of the independent <I>time</I> variable
* @param primary array containing the current value of the primary state vector
* @param primaryDot array containing the derivative of the primary state vector
* @param secondary array containing the current value of the secondary state vector
* @return space view of the state
*/
private FieldSpacecraftState<T> convert(final T t, final T[] primary,
final T[] primaryDot, final T[] secondary) {
FieldSpacecraftState<T> initialState = stateMapper.mapArrayToState(t, primary, primaryDot, PropagationType.MEAN);
for (final FieldAdditionalDerivativesProvider<T> provider : additionalDerivativesProviders) {
final String name = provider.getName();
final int offset = secondaryOffsets.get(name);
final int dimension = provider.getDimension();
initialState = initialState.addAdditionalState(name, Arrays.copyOfRange(secondary, offset, offset + dimension));
}
return updateAdditionalStates(initialState);
}
}
/** Adapt an {@link org.orekit.propagation.events.FieldEventDetector<T>}
* to Hipparchus {@link org.hipparchus.ode.events.FieldODEEventDetector<T>} interface.
* @author Fabien Maussion
*/
private class FieldAdaptedEventDetector implements FieldODEEventDetector<T> {
/** Underlying event detector. */
private final FieldEventDetector<T> detector;
/** Underlying event handler.
* @since 12.0
*/
private final FieldEventHandler<T> handler;
/** Time of the previous call to g. */
private T lastT;
/** Value from the previous call to g. */
private T lastG;
/** Build a wrapped event detector.
* @param detector event detector to wrap
*/
FieldAdaptedEventDetector(final FieldEventDetector<T> detector) {
this.detector = detector;
this.handler = detector.getHandler();
this.lastT = getField().getZero().add(Double.NaN);
this.lastG = getField().getZero().add(Double.NaN);
}
/** {@inheritDoc} */
@Override
public FieldAdaptableInterval<T> getMaxCheckInterval() {
return (state, isForward) -> detector.getMaxCheckInterval().currentInterval(convert(state), isForward);
}
/** {@inheritDoc} */
@Override
public int getMaxIterationCount() {
return detector.getMaxIterationCount();
}
/** {@inheritDoc} */
@Override
public FieldBracketingNthOrderBrentSolver<T> getSolver() {
final T zero = detector.getThreshold().getField().getZero();
return new FieldBracketingNthOrderBrentSolver<>(zero, detector.getThreshold(), zero, 5);
}
/** {@inheritDoc} */
@Override
public void init(final FieldODEStateAndDerivative<T> s0, final T t) {
detector.init(convert(s0), stateMapper.mapDoubleToDate(t));
this.lastT = getField().getZero().add(Double.NaN);
this.lastG = getField().getZero().add(Double.NaN);
}
/** {@inheritDoc} */
public T g(final FieldODEStateAndDerivative<T> s) {
if (!Precision.equals(lastT.getReal(), s.getTime().getReal(), 0)) {
lastT = s.getTime();
lastG = detector.g(convert(s));
}
return lastG;
}
/** {@inheritDoc} */
public FieldODEEventHandler<T> getHandler() {
return new FieldODEEventHandler<T>() {
/** {@inheritDoc} */
public Action eventOccurred(final FieldODEStateAndDerivative<T> s,
final FieldODEEventDetector<T> d,
final boolean increasing) {
return handler.eventOccurred(convert(s), detector, increasing);
}
/** {@inheritDoc} */
@Override
public FieldODEState<T> resetState(final FieldODEEventDetector<T> d,
final FieldODEStateAndDerivative<T> s) {
final FieldSpacecraftState<T> oldState = convert(s);
final FieldSpacecraftState<T> newState = handler.resetState(detector, oldState);
stateChanged(newState);
// main part
final T[] primary = MathArrays.buildArray(getField(), s.getPrimaryStateDimension());
stateMapper.mapStateToArray(newState, primary, null);
// secondary part
final T[][] secondary = MathArrays.buildArray(getField(), 1, additionalDerivativesProviders.size());
for (final FieldAdditionalDerivativesProvider<T> provider : additionalDerivativesProviders) {
final String name = provider.getName();
final int offset = secondaryOffsets.get(name);
final int dimension = provider.getDimension();
System.arraycopy(newState.getAdditionalState(name), 0, secondary[0], offset, dimension);
}
return new FieldODEState<>(newState.getDate().durationFrom(getStartDate()),
primary, secondary);
}
};
}
}
/** Adapt an {@link org.orekit.propagation.sampling.FieldOrekitStepHandler<T>}
* to Hipparchus {@link FieldODEStepHandler<T>} interface.
* @author Luc Maisonobe
*/
private class FieldAdaptedStepHandler implements FieldODEStepHandler<T> {
/** Underlying handler. */
private final FieldOrekitStepHandler<T> handler;
/** Build an instance.
* @param handler underlying handler to wrap
*/
FieldAdaptedStepHandler(final FieldOrekitStepHandler<T> handler) {
this.handler = handler;
}
/** {@inheritDoc} */
@Override
public void init(final FieldODEStateAndDerivative<T> s0, final T t) {
handler.init(convert(s0), stateMapper.mapDoubleToDate(t));
}
/** {@inheritDoc} */
public void handleStep(final FieldODEStateInterpolator<T> interpolator) {
handler.handleStep(new FieldAdaptedStepInterpolator(interpolator));
}
/** {@inheritDoc} */
@Override
public void finish(final FieldODEStateAndDerivative<T> finalState) {
handler.finish(convert(finalState));
}
}
/** Adapt an {@link org.orekit.propagation.sampling.FieldOrekitStepInterpolator<T>}
* to Hipparchus {@link FieldODEStateInterpolator<T>} interface.
* @author Luc Maisonobe
*/
private class FieldAdaptedStepInterpolator implements FieldOrekitStepInterpolator<T> {
/** Underlying raw rawInterpolator. */
private final FieldODEStateInterpolator<T> mathInterpolator;
/** Build an instance.
* @param mathInterpolator underlying raw interpolator
*/
FieldAdaptedStepInterpolator(final FieldODEStateInterpolator<T> mathInterpolator) {
this.mathInterpolator = mathInterpolator;
}
/** {@inheritDoc}} */
@Override
public FieldSpacecraftState<T> getPreviousState() {
return convert(mathInterpolator.getPreviousState());
}
/** {@inheritDoc}} */
@Override
public FieldSpacecraftState<T> getCurrentState() {
return convert(mathInterpolator.getCurrentState());
}
/** {@inheritDoc}} */
@Override
public FieldSpacecraftState<T> getInterpolatedState(final FieldAbsoluteDate<T> date) {
return convert(mathInterpolator.getInterpolatedState(date.durationFrom(getStartDate())));
}
/** Check is integration direction is forward in date.
* @return true if integration is forward in date
*/
public boolean isForward() {
return mathInterpolator.isForward();
}
/** {@inheritDoc}} */
@Override
public FieldAdaptedStepInterpolator restrictStep(final FieldSpacecraftState<T> newPreviousState,
final FieldSpacecraftState<T> newCurrentState) {
try {
final AbstractFieldODEStateInterpolator<T> aosi = (AbstractFieldODEStateInterpolator<T>) mathInterpolator;
return new FieldAdaptedStepInterpolator(aosi.restrictStep(convert(newPreviousState),
convert(newCurrentState)));
} catch (ClassCastException cce) {
// this should never happen
throw new OrekitInternalError(cce);
}
}
}
/** Specialized step handler storing interpolators for ephemeris generation.
* @since 11.0
*/
private class FieldStoringStepHandler implements FieldODEStepHandler<T>, FieldEphemerisGenerator<T> {
/** Underlying raw mathematical model. */
private FieldDenseOutputModel<T> model;
/** the user supplied end date. Propagation may not end on this date. */
private FieldAbsoluteDate<T> endDate;
/** Generated ephemeris. */
private FieldBoundedPropagator<T> ephemeris;
/** Last interpolator handled by the object.*/
private FieldODEStateInterpolator<T> lastInterpolator;
/** Set the end date.
* @param endDate end date
*/
public void setEndDate(final FieldAbsoluteDate<T> endDate) {
this.endDate = endDate;
}
/** {@inheritDoc} */
@Override
public void init(final FieldODEStateAndDerivative<T> s0, final T t) {
this.model = new FieldDenseOutputModel<>();
model.init(s0, t);
// ephemeris will be generated when last step is processed
this.ephemeris = null;
this.lastInterpolator = null;
}
/** {@inheritDoc} */
@Override
public FieldBoundedPropagator<T> getGeneratedEphemeris() {
// Each time we try to get the ephemeris, rebuild it using the last data.
buildEphemeris();
return ephemeris;
}
/** {@inheritDoc} */
@Override
public void handleStep(final FieldODEStateInterpolator<T> interpolator) {
model.handleStep(interpolator);
lastInterpolator = interpolator;
}
/** {@inheritDoc} */
@Override
public void finish(final FieldODEStateAndDerivative<T> finalState) {
buildEphemeris();
}
/** Method used to produce ephemeris at a given time.
* Can be used at multiple times, updating the ephemeris to
* its last state.
*/
private void buildEphemeris() {
// buildEphemeris was built in order to allow access to what was previously the finish method.
// This now allows to call it through getGeneratedEphemeris, therefore through an external call,
// which was not previously the case.
// Update the model's finalTime with the last interpolator.
model.finish(lastInterpolator.getCurrentState());
// set up the boundary dates
final T tI = model.getInitialTime();
final T tF = model.getFinalTime();
// tI is almost? always zero
final FieldAbsoluteDate<T> startDate =
stateMapper.mapDoubleToDate(tI);
final FieldAbsoluteDate<T> finalDate =
stateMapper.mapDoubleToDate(tF, this.endDate);
final FieldAbsoluteDate<T> minDate;
final FieldAbsoluteDate<T> maxDate;
if (tF.getReal() < tI.getReal()) {
minDate = finalDate;
maxDate = startDate;
} else {
minDate = startDate;
maxDate = finalDate;
}
// get the initial additional states that are not managed
final FieldArrayDictionary<T> unmanaged = new FieldArrayDictionary<>(startDate.getField());
for (final FieldArrayDictionary<T>.Entry initial : getInitialState().getAdditionalStatesValues().getData()) {
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
unmanaged.put(initial.getKey(), initial.getValue());
}
}
// get the names of additional states managed by differential equations
final String[] names = new String[additionalDerivativesProviders.size()];
final int[] dimensions = new int[additionalDerivativesProviders.size()];
for (int i = 0; i < names.length; ++i) {
names[i] = additionalDerivativesProviders.get(i).getName();
dimensions[i] = additionalDerivativesProviders.get(i).getDimension();
}
// create the ephemeris
ephemeris = new FieldIntegratedEphemeris<>(startDate, minDate, maxDate,
stateMapper, propagationType, model,
unmanaged, getAdditionalStateProviders(),
names, dimensions);
}
}
/** Wrapper for resetting an integrator handlers.
* <p>
* This class is intended to be used in a try-with-resource statement.
* If propagator-specific event handlers and step handlers are added to
* the integrator in the try block, they will be removed automatically
* when leaving the block, so the integrator only keep its own handlers
* between calls to {@link FieldAbstractIntegratedPropagator#propagate(FieldAbsoluteDate, FieldAbsoluteDate).
* </p>
* @param <T> the type of the field elements
* @since 11.0
*/
private static class IntegratorResetter<T extends CalculusFieldElement<T>> implements AutoCloseable {
/** Wrapped integrator. */
private final FieldODEIntegrator<T> integrator;
/** Initial event detectors list. */
private final List<FieldODEEventDetector<T>> detectors;
/** Initial step handlers list. */
private final List<FieldODEStepHandler<T>> stepHandlers;
/** Simple constructor.
* @param integrator wrapped integrator
*/
IntegratorResetter(final FieldODEIntegrator<T> integrator) {
this.integrator = integrator;
this.detectors = new ArrayList<>(integrator.getEventDetectors());
this.stepHandlers = new ArrayList<>(integrator.getStepHandlers());
}
/** {@inheritDoc}
* <p>
* Reset event handlers and step handlers back to the initial list
* </p>
*/
@Override
public void close() {
// reset event handlers
integrator.clearEventDetectors();
detectors.forEach(integrator::addEventDetector);
// reset step handlers
integrator.clearStepHandlers();
stepHandlers.forEach(integrator::addStepHandler);
}
}
}