agi.foundation.propagators.advanced

(agi.foundation.models-2024r2.jar)

Class PropagationStateElementConverter

java.lang.Object

agi.foundation.propagators.advanced.PropagationStateElementConverter

All Implemented Interfaces:

ICloneWithContext, IThreadAware

Direct Known Subclasses:

AircraftStateElementConverter, CartesianStateElementConverter, MatrixStateElementConverter, RotationVectorAngularVelocityStateElementConverter

public abstract class PropagationStateElementConverter
extends Object
implements IThreadAware

Base class for output associated with a PropagationStateElement. This represents the indexed state, and a means of converting the raw output information back into useful information specific to this element.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PropagationStateElementConverter(PropagationStateElementConverter existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
protected	PropagationStateElementConverter(String identification, Motion1<int[]> stateIndices, Motion1<double[]> initialState) Initializes a new instance.
protected	PropagationStateElementConverter(String identification, Motion1<int[]> stateIndices, Motion1<double[]> initialState, Motion1<double[]> weights) Initializes a new instance.

Method Summary

Modifier and Type	Method and Description
abstract boolean	adjustStateFromElement(double[] overallRawState, Motion1<double[]> stateElementValues) Adjust the subset of the overall raw state corresponding to this element to new values.
abstract <T> boolean	adjustStateWithType(double[] overallRawState, Motion1<T> newStateElement) Adjust the subset of the raw state corresponding to this element to new values.
abstract Object	clone(CopyContext context) Clones this object using the specified context.
abstract <T> Motion1<T>	convertState(double[] overallState) Convert the raw state into this instance's TypeOfOutput (get) and its derivatives.
Motion1<double[]>	getAdaptiveWeights() Gets the weights to be applied to the state elements when computing the error which determines how to adapt the step size during integration.
abstract int	getDimension() Gets the number of parameters (per Order (get)) within this element.
abstract Motion1<double[]>	getElementFromState(double[] overallState) Produces this state element's values and their derivatives from the overall raw state.
String	getIdentification() Gets the string identifying this instance in the overall output.
Motion1<double[]>	getInitialState() Gets the initial values of this element of the state and their derivatives.
boolean	getIsThreadSafe() Gets a value indicating whether the methods on this instance are safe to call from multiple threads simultaneously.
int	getOrder() Gets the order of the differential equation corresponding to this element.
Motion1<int[]>	getStateIndices() Gets the indices locating each variable of this element within the overall state.
abstract Class<?>	getTypeOfOutput() Gets the type associated with the output of this instance.
protected void	setAdaptiveWeights(Motion1<double[]> value) Sets the weights to be applied to the state elements when computing the error which determines how to adapt the step size during integration.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PropagationStateElementConverter

protected PropagationStateElementConverter(String identification,
                                           @Nonnull
                                           Motion1<int[]> stateIndices,
                                           @Nonnull
                                           Motion1<double[]> initialState)

Initializes a new instance.

Parameters:

identification - A string identifying this instance in the overall output.

stateIndices - The indices of the individual values and their derivatives in the overall state.

initialState - The values of the state at the epoch of the overall NumericalPropagatorDefinition.

PropagationStateElementConverter

protected PropagationStateElementConverter(String identification,
                                           @Nonnull
                                           Motion1<int[]> stateIndices,
                                           @Nonnull
                                           Motion1<double[]> initialState,
                                           @Nonnull
                                           Motion1<double[]> weights)

Initializes a new instance.

Parameters:

identification - A string identifying this instance in the overall output.

stateIndices - The indices of the individual values and their derivatives in the overall state.

initialState - The values of the state at the epoch of the overall NumericalPropagatorDefinition.

weights - A set of weights associated with each value in the state to use when performing adaptive step control with an AdaptiveNumericalIntegrator.

PropagationStateElementConverter

protected PropagationStateElementConverter(@Nonnull
                                           PropagationStateElementConverter existingInstance,
                                           @Nonnull
                                           CopyContext context)

Initializes a new instance as a copy of an existing instance.

See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor in a derived class.

Parameters:

existingInstance - The existing instance to copy.

context - A CopyContext that controls the depth of the copy.

Throws:

ArgumentNullException - Thrown when existingInstance or context is null.

Method Detail

clone

public abstract Object clone(CopyContext context)

Clones this object using the specified context.

This method should be implemented to call a copy constructor on the class of the object being cloned. The copy constructor should take the CopyContext as a parameter in addition to the existing instance to copy. The copy constructor should first call CopyContext.addObjectMapping(T, T) to identify the newly constructed instance as a copy of the existing instance. It should then copy all fields, using CopyContext.updateReference(T) to copy any reference fields.

A typical implementation of ICloneWithContext:

public static class MyClass implements ICloneWithContext {
    public MyClass(MyClass existingInstance, CopyContext context) {
        context.addObjectMapping(existingInstance, this);
        someReference = context.updateReference(existingInstance.someReference);
    }

    @Override
    public final Object clone(CopyContext context) {
        return new MyClass(this, context);
    }

    private Object someReference;
}

In general, all fields that are reference types should be copied with a call to CopyContext.updateReference(T). There are a couple of exceptions:

1. Fields that are aggregate parts of the object should always be copied. A referenced object is an aggregate if properties or methods on the object being copied can modify the externally-visible value of the referenced object.
2. If the semantics of the referenced object require that it have a single parent, owner, context, etc., and the object being copied is that parent, owner, or context, then the referenced object should always be copied.

If one of these exceptions applies, the CopyContext should be given an opportunity to update the reference before the reference is copied explicitly. Use CopyContext.updateReference(T) to update the reference. If CopyContext.updateReference(T) returns the original object, indicating that the context does not have a replacement registered, then copy the object manually by invoking a Clone method, a copy constructor, or by manually constructing a new instance and copying the values.

alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
    alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}

If you are implementing an evaluator (a class that implements IEvaluator), the IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) method shares some responsibilities with the copy context constructor. Code duplication can be avoided by doing the following:

1. For references to other evaluators ONLY, simply assign the reference in the constructor instead of calling CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to non-evaluators.
2. Call IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the same CopyContext passed to the constructor.
3. Implement IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as normal. See the reference documentation for IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) for more information on implementing that method.

public MyClass(MyClass existingInstance, CopyContext context) {
    super(existingInstance, context);
    someReference = context.updateReference(existingInstance.someReference);
    evaluatorReference = existingInstance.evaluatorReference;
    updateEvaluatorReferences(context);
}

@Override
public void updateEvaluatorReferences(CopyContext context) {
    evaluatorReference = context.updateReference(evaluatorReference);
}

@Override
public Object clone(CopyContext context) {
    return new MyClass(this, context);
}

private Object someReference;
private IEvaluator evaluatorReference;

Specified by:

clone in interface ICloneWithContext

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

getIsThreadSafe

public final boolean getIsThreadSafe()

Gets a value indicating whether the methods on this instance are safe to call from multiple threads simultaneously.

If this property is true, all methods and properties are guaranteed to be thread safe. Conceptually, an object that returns true for this method acts as if there is a lock protecting each method and property such that only one thread at a time can be inside any method or property in the class. In reality, such locks are generally not used and are in fact discouraged. However, the user must not experience any exceptions or inconsistent behavior that would not be experienced if such locks were used.

If this property is false, the behavior when using this class from multiple threads simultaneously is undefined and may include inconsistent results and exceptions. Clients wishing to use multiple threads should call CopyForAnotherThread.copy(T) to get a separate instance of the object for each thread.

Specified by:

getIsThreadSafe in interface IThreadAware

getIdentification

public final String getIdentification()

Gets the string identifying this instance in the overall output.

getStateIndices

@Nonnull
public final Motion1<int[]> getStateIndices()

Gets the indices locating each variable of this element within the overall state. The motion represents the value of this state element and its derivatives up to but not including the Order (get) of the differential equation defining the state's derivative. The indices will be set by the NumericalPropagatorDefinition when this element is added.

getInitialState

@Nonnull
public final Motion1<double[]> getInitialState()

Gets the initial values of this element of the state and their derivatives. The size of the initial state is its Dimension (get) and the order of the motion is one less than the Order (get) of the differential equation defining the derivative of this element.

getOrder

public int getOrder()

Gets the order of the differential equation corresponding to this element. This corresponds to one greater than the Order of the InitialState (get).

getDimension

public abstract int getDimension()

Gets the number of parameters (per Order (get)) within this element.

getAdaptiveWeights

@Nonnull
public final Motion1<double[]> getAdaptiveWeights()

Gets the weights to be applied to the state elements when computing the error which determines how to adapt the step size during integration. This is in addition to any weights used in the integration algorithm itself. The weights are initialized to default values of one based on the Order (get) and Dimension (get) of the state element. The order of the motion is one less than the Order (get) and each array is of length Dimension (get).

setAdaptiveWeights

protected final void setAdaptiveWeights(@Nonnull
                                        Motion1<double[]> value)

Sets the weights to be applied to the state elements when computing the error which determines how to adapt the step size during integration. This is in addition to any weights used in the integration algorithm itself. The weights are initialized to default values of one based on the Order (get) and Dimension (get) of the state element. The order of the motion is one less than the Order (get) and each array is of length Dimension (get).

getTypeOfOutput

@Nonnull
public abstract Class<?> getTypeOfOutput()

Gets the type associated with the output of this instance.

convertState

@Nonnull
public abstract <T> Motion1<T> convertState(double[] overallState)

Convert the raw state into this instance's TypeOfOutput (get) and its derivatives.

Type Parameters:

T - The TypeOfOutput (get) produced by this instance.

Parameters:

overallState - The raw state to convert.

Returns:

The value and its derivatives corresponding to the state.

getElementFromState

@Nonnull
public abstract Motion1<double[]> getElementFromState(double[] overallState)

Produces this state element's values and their derivatives from the overall raw state.

Parameters:

overallState - The overall raw state from which to produce this element's array.

Returns:

A representation of the values of this state as arrays of length Dimension (get) in a motion of this element's Order (get) minus one.

adjustStateWithType

public abstract <T> boolean adjustStateWithType(double[] overallRawState,
                                                @Nonnull
                                                Motion1<T> newStateElement)

Adjust the subset of the raw state corresponding to this element to new values.

Type Parameters:

T - The type corresponding to the TypeOfOutput (get) of this element.

Parameters:

overallRawState - The overall raw state to adjust.

newStateElement - The new values and derivatives for the requested element.

Returns:

True if the update was successful. Otherwise, if the specified new element values did not contain enough derivatives or there was some other problem completing the update, this returns false.

adjustStateFromElement

public abstract boolean adjustStateFromElement(double[] overallRawState,
                                               @Nonnull
                                               Motion1<double[]> stateElementValues)

Adjust the subset of the overall raw state corresponding to this element to new values.

Parameters:

overallRawState - The overall raw state to adjust.

stateElementValues - The new values and derivatives for the requested element represented as an array. To obtain an instance of this array, call PropagationStateElementConverter.getElementFromState(double[]).

Returns:

True if the update was successful. Otherwise, if the specified new element values did not contain enough derivatives or there was some other problem completing the update, this returns false.