agi.foundation.propagators

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

Class PropagationVector

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.propagators.advanced.PropagationStateElement

agi.foundation.propagators.PropagationVector

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

public class PropagationVector
extends PropagationStateElement

A PropagationStateElement representing a vector value to be integrated over time.

Constructor Summary

Constructors

Modifier	Constructor and Description
	PropagationVector() Initializes a new instance.
	PropagationVector(Cartesian... initialValues) Initializes a new instance.
protected	PropagationVector(PropagationVector existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(PropagationStateElement other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(PropagationVector other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
Object	clone(CopyContext context) Clones this object using the specified context.
protected int	computeCurrentDefinitionHashCode() Computes a hash code based on the current properties of this object.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
protected void	freezeAggregatedObjects() Called by DefinitionalObject.freeze() to also freeze any objects that are considered to be a part of this object.
Motion1<double[]>	getAdaptiveWeights() Gets the weights to be applied to the scalar values when computing the error which determines how to adapt the step size during integration.
PropagationStateElementConverter	getConverter(EvaluatorGroup group, Motion1<int[]> stateInputIndices) Gets an instance of an output type which can convert the output of propagation back into the native type of this state element.
PropagationStateElementEvaluator	getDerivatives(EvaluatorGroup group) This is used by the NumericalPropagatorDefinition to obtain an instance of a state element evaluator that can compute the derivatives of this element of the state during propagation.
int	getDimension() Gets the number of parameters (per Order (get)) within this element.
Motion1<Cartesian>	getInitialState() Gets the initial vector and its derivatives up to the order of the VectorDerivative (get / set).
Vector	getIntegrationValue() Gets a Vector object that is parameterized on a vector value in the state during integration.
int	getOrder() Gets the order of the differential equation corresponding to this element.
Axes	getPropagationAxes() Gets the Axes in which the propagation occurs.
PropagationStateParameter	getStateParameter() Gets a parameter which represents the state during propagation.
Vector	getVectorDerivative() Gets the derivative of the highest Order (get) which specifies the motion of this vector parameter over time.
void	setAdaptiveWeights(Motion1<double[]> value) Sets the weights to be applied to the scalar values when computing the error which determines how to adapt the step size during integration.
void	setInitialState(Motion1<Cartesian> value) Sets the initial vector and its derivatives up to the order of the VectorDerivative (get / set).
void	setPropagationAxes(Axes value) Sets the Axes in which the propagation occurs.
void	setStateParameter(PropagationStateParameter value) Sets a parameter which represents the state during propagation.
void	setVectorDerivative(Vector value) Sets the derivative of the highest Order (get) which specifies the motion of this vector parameter over time.

Methods inherited from class agi.foundation.propagators.advanced.PropagationStateElement

checkForSameDefinition, getIdentification, getIncludeHighestDerivativeInOutput, getStateUpdater, setIdentification, setIncludeHighestDerivativeInOutput

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozen

Methods inherited from class java.lang.Object

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

Constructor Detail

PropagationVector

public PropagationVector()

Initializes a new instance.

PropagationVector

public PropagationVector(@Nonnull
                         Cartesian... initialValues)

Initializes a new instance.

Parameters:

initialValues - The initial value of the vector and its derivatives at the starting epoch of propagation.

PropagationVector

protected PropagationVector(@Nonnull
                            PropagationVector 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 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

Specified by:

clone in class DefinitionalObject

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

checkForSameDefinition

protected final boolean checkForSameDefinition(PropagationStateElement other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Specified by:

checkForSameDefinition in class PropagationStateElement

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

checkForSameDefinition

protected boolean checkForSameDefinition(PropagationVector other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

computeCurrentDefinitionHashCode

protected int computeCurrentDefinitionHashCode()

Computes a hash code based on the current properties of this object. Derived classes MUST override this method and compute a hash code that combines: a unique hash code seed, the base implementation result, and the hash codes of all new fields introduced by the derived class which are used in the PropagationVector.checkForSameDefinition(agi.foundation.propagators.advanced.PropagationStateElement) method.

Overrides:

computeCurrentDefinitionHashCode in class PropagationStateElement

Returns:

The computed hash code.

enumerateDependencies

public void enumerateDependencies(DependencyEnumerator enumerator)

Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon. Derived classes which contain additional dependencies MUST override this method, call the base implementation, and enumerate dependencies introduced by the derived class.

Specified by:

enumerateDependencies in interface IEnumerateDependencies

Overrides:

enumerateDependencies in class DefinitionalObject

Parameters:

enumerator - The enumerator that is informed of the dependencies of this object.

freezeAggregatedObjects

protected void freezeAggregatedObjects()

Called by DefinitionalObject.freeze() to also freeze any objects that are considered to be a part of this object. Derived classes which contain additional aggregated objects MUST override this method, call the base implementation, and freeze aggregated objects introduced by the derived class. The objects that need to be frozen in this method are frequently created in this object's constructor and are not settable via properties.

Overrides:

freezeAggregatedObjects in class DefinitionalObject

getDimension

public int getDimension()

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

Specified by:

getDimension in class PropagationStateElement

getOrder

public int getOrder()

Gets the order of the differential equation corresponding to this element.

Specified by:

getOrder in class PropagationStateElement

getInitialState

@Nonnull
public final Motion1<Cartesian> getInitialState()

Gets the initial vector and its derivatives up to the order of the VectorDerivative (get / set).

setInitialState

public final void setInitialState(@Nonnull
                                  Motion1<Cartesian> value)

Sets the initial vector and its derivatives up to the order of the VectorDerivative (get / set).

getAdaptiveWeights

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

Gets the weights to be applied to the scalar values 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. If not set, the weights are initialized to 1.0 as a default value.

setAdaptiveWeights

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

Sets the weights to be applied to the scalar values 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. If not set, the weights are initialized to 1.0 as a default value.

getIntegrationValue

public final Vector getIntegrationValue()

Gets a Vector object that is parameterized on a vector value in the state during integration. This vector is only valid while the NumericalPropagator is running. For more general use, a VectorInterpolator should be created from the NumericalPropagationStateHistory produced by the propagator.

getVectorDerivative

public final Vector getVectorDerivative()

Gets the derivative of the highest Order (get) which specifies the motion of this vector parameter over time. The order that this vector represents will be determined by the number of values entered for the InitialState (get / set) (its Order plus one).

setVectorDerivative

public final void setVectorDerivative(Vector value)

Sets the derivative of the highest Order (get) which specifies the motion of this vector parameter over time. The order that this vector represents will be determined by the number of values entered for the InitialState (get / set) (its Order plus one).

getPropagationAxes

public final Axes getPropagationAxes()

Gets the Axes in which the propagation occurs. These are the axes in which the VectorDerivative (get / set) is represented.

setPropagationAxes

public final void setPropagationAxes(Axes value)

Sets the Axes in which the propagation occurs. These are the axes in which the VectorDerivative (get / set) is represented.

getStateParameter

public PropagationStateParameter getStateParameter()

Gets a parameter which represents the state during propagation. In general, users should never need to explicitly set this property. It should only be set when multiple NumericalPropagator objects are running in the same EvaluatorGroup, such as when elements of a state require additional instances of a NumericalPropagator inside their implementation in order to produce their values. In such cases, it may be necessary to distinguish between the state of the exterior propagator and the state of the interior propagator. In these cases, it is up to the user to ensure that both the state and all of its elements are configured with the same parameter. Otherwise, the state will throw an exception when creating its propagator.

Specified by:

getStateParameter in class PropagationStateElement

setStateParameter

public void setStateParameter(PropagationStateParameter value)

Sets a parameter which represents the state during propagation. In general, users should never need to explicitly set this property. It should only be set when multiple NumericalPropagator objects are running in the same EvaluatorGroup, such as when elements of a state require additional instances of a NumericalPropagator inside their implementation in order to produce their values. In such cases, it may be necessary to distinguish between the state of the exterior propagator and the state of the interior propagator. In these cases, it is up to the user to ensure that both the state and all of its elements are configured with the same parameter. Otherwise, the state will throw an exception when creating its propagator.

Specified by:

setStateParameter in class PropagationStateElement

getConverter

public PropagationStateElementConverter getConverter(EvaluatorGroup group,
                                                     @Nonnull
                                                     Motion1<int[]> stateInputIndices)

Gets an instance of an output type which can convert the output of propagation back into the native type of this state element. This method is also responsible for configuring the state parameter and the state input indices on any parameterized geometry types used by this element. Each parameterized geometry type will have a static configuration method which will allow it to configure itself in a particular EvaluatorGroup.

Specified by:

getConverter in class PropagationStateElement

Parameters:

group - The evaluator group in which to configure the parameters.

stateInputIndices - The set of indices corresponding to the location of each value or derivative of this state element in the overall state.

Returns:

The output instance associated with this state element.

getDerivatives

public PropagationStateElementEvaluator getDerivatives(EvaluatorGroup group)

This is used by the NumericalPropagatorDefinition to obtain an instance of a state element evaluator that can compute the derivatives of this element of the state during propagation. It cannot be used outside of a NumericalPropagator as the geometry for the propagation state will be unavailable.

Specified by:

getDerivatives in class PropagationStateElement

Parameters:

group - The group in which to create the evaluator and its dependents.

Returns:

The evaluator that can compute the derivatives of this element of the state.