agi.foundation.numericalmethods

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

Class TargetedSegmentListDifferentialCorrector

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.segmentpropagation.TargetedSegmentListOperator

agi.foundation.numericalmethods.TargetedSegmentListDifferentialCorrector

All Implemented Interfaces:

IDisposable, ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, AutoCloseable

public class TargetedSegmentListDifferentialCorrector
extends TargetedSegmentListOperator
implements IDisposable

When using the Segment Propagation Library, there will be times when you don't know exactly what a value should be set to. For example, it may be that you don't know when a StoppingCondition should stop, or where your satellite should start propagating from in an InitialStateSegment. This type provides a means to solve for such settings in your segments by using some sort of MultivariableFunctionSolver to drive the trajectory to a set of constraint values.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
void	addNormalFunctionEvaluationEvent(EventHandler<SolverFunctionEvaluatedEventArgs> value) An event that gets raised when the nominal orbit is evaluated with no perturbations.
void	addPerturbedFunctionEvaluationEvent(EventHandler<SolverFunctionEvaluatedEventArgs> value) An event that gets raised when a perturbed orbit is computed.
protected boolean	checkForSameDefinition(TargetedSegmentListDifferentialCorrector other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(TargetedSegmentListOperator 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	dispose() Releases any resources associated with this instance.
protected void	dispose(boolean disposing) Releases any resources associated with this instance.
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.
ArrayList<SegmentPropagatorConstraint>	getConstraints() Gets the constraints that the Variables (get) will attempt to drive the trajectory of the parent TargetedSegmentList to.
FiniteDifferenceMethod	getDifferenceMethod() Gets the difference method used to compute the derivative of the function.
int	getMaximumIterations() Gets the maximum number of iterations this operator will take to find a solution.
boolean	getOnlyStoreFinalResults() Gets a value indicating whether this operator should report only the final results or all iterations/computations.
TargetedSegmentListOperatorEvaluator	getOperatorEvaluator(EvaluatorGroup group) Creates and returns the fully configured TargetedSegmentListOperatorEvaluator for use in a TargetedSegmentLists propagator.
MultivariableFunctionSolver	getSolver() Gets the MultivariableFunctionSolver that will be used to drive the trajectory to the constraints specified.
ArrayList<SegmentPropagatorVariable>	getVariables() Gets the variables that will change the trajectory to satisfy the Constraints (get).
void	removeNormalFunctionEvaluationEvent(EventHandler<SolverFunctionEvaluatedEventArgs> value) An event that gets raised when the nominal orbit is evaluated with no perturbations.
void	removePerturbedFunctionEvaluationEvent(EventHandler<SolverFunctionEvaluatedEventArgs> value) An event that gets raised when a perturbed orbit is computed.
void	setDifferenceMethod(FiniteDifferenceMethod value) Sets the difference method used to compute the derivative of the function.
void	setMaximumIterations(int value) Sets the maximum number of iterations this operator will take to find a solution.
void	setOnlyStoreFinalResults(boolean value) Sets a value indicating whether this operator should report only the final results or all iterations/computations.
void	setSolver(MultivariableFunctionSolver value) Sets the MultivariableFunctionSolver that will be used to drive the trajectory to the constraints specified.
String	toString() Returns a string representation of the object.

Methods inherited from class agi.foundation.segmentpropagation.TargetedSegmentListOperator

checkForSameDefinition, getName, setName

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, wait, wait, wait

Methods inherited from interface agi.foundation.compatibility.IDisposable

close

Constructor Detail

TargetedSegmentListDifferentialCorrector

public TargetedSegmentListDifferentialCorrector()

Initializes a new instance.

TargetedSegmentListDifferentialCorrector

protected TargetedSegmentListDifferentialCorrector(@Nonnull
                                                   TargetedSegmentListDifferentialCorrector 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 TargetedSegmentListOperator

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

dispose

public final void dispose()

Releases any resources associated with this instance.

Specified by:

dispose in interface IDisposable

dispose

protected void dispose(boolean disposing)

Releases any resources associated with this instance.

Parameters:

disposing - true to release both managed and unmanaged resources; false to release only unmanaged resources.

checkForSameDefinition

protected final boolean checkForSameDefinition(TargetedSegmentListOperator 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 TargetedSegmentListOperator

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(TargetedSegmentListDifferentialCorrector 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 TargetedSegmentListDifferentialCorrector.checkForSameDefinition(agi.foundation.segmentpropagation.TargetedSegmentListOperator) method.

Overrides:

computeCurrentDefinitionHashCode in class TargetedSegmentListOperator

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

getSolver

@Nonnull
public final MultivariableFunctionSolver getSolver()

Gets the MultivariableFunctionSolver that will be used to drive the trajectory to the constraints specified. All properties on the Solver (get / set) should be set as needed except for the Function (get / set), Constraints (get) and Variables (get).

setSolver

public final void setSolver(@Nonnull
                            MultivariableFunctionSolver value)

Sets the MultivariableFunctionSolver that will be used to drive the trajectory to the constraints specified. All properties on the Solver (get / set) should be set as needed except for the Function (get / set), Constraints (get) and Variables (get).

getVariables

@Nonnull
public final ArrayList<SegmentPropagatorVariable> getVariables()

Gets the variables that will change the trajectory to satisfy the Constraints (get). These Variables (get) will provide the SolverVariableSettings to the Solver (get / set) when TargetedSegmentListDifferentialCorrector.getOperatorEvaluator(agi.foundation.EvaluatorGroup) is called.

getConstraints

@Nonnull
public final ArrayList<SegmentPropagatorConstraint> getConstraints()

Gets the constraints that the Variables (get) will attempt to drive the trajectory of the parent TargetedSegmentList to. These Constraints (get) will provide the SolverConstraintSettings to the Solver (get / set) when TargetedSegmentListDifferentialCorrector.getOperatorEvaluator(agi.foundation.EvaluatorGroup) is called.

getOnlyStoreFinalResults

public final boolean getOnlyStoreFinalResults()

Gets a value indicating whether this operator should report only the final results or all iterations/computations. For example, it is possible that this operator will iterate to a solution and that each iteration will produce a large ephemeris. If memory use is a concern and you do not need to do analysis on the iterations, ensure this is true. Conversely, if debugging the operator's performance is needed set this property to false. By default this is true.

setOnlyStoreFinalResults

public final void setOnlyStoreFinalResults(boolean value)

Sets a value indicating whether this operator should report only the final results or all iterations/computations. For example, it is possible that this operator will iterate to a solution and that each iteration will produce a large ephemeris. If memory use is a concern and you do not need to do analysis on the iterations, ensure this is true. Conversely, if debugging the operator's performance is needed set this property to false. By default this is true.

getMaximumIterations

public final int getMaximumIterations()

Gets the maximum number of iterations this operator will take to find a solution. By default, this is set to 50.

setMaximumIterations

public final void setMaximumIterations(int value)

Sets the maximum number of iterations this operator will take to find a solution. By default, this is set to 50.

getDifferenceMethod

@Nonnull
public final FiniteDifferenceMethod getDifferenceMethod()

Gets the difference method used to compute the derivative of the function.

setDifferenceMethod

public final void setDifferenceMethod(@Nonnull
                                      FiniteDifferenceMethod value)

Sets the difference method used to compute the derivative of the function.

toString

public String toString()

Description copied from class: java.lang.Object

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

Overrides:

toString in class Object

Returns:

a string representation of the object.

getOperatorEvaluator

public TargetedSegmentListOperatorEvaluator getOperatorEvaluator(EvaluatorGroup group)

Creates and returns the fully configured TargetedSegmentListOperatorEvaluator for use in a TargetedSegmentLists propagator.

Specified by:

getOperatorEvaluator in class TargetedSegmentListOperator

Parameters:

group - The EvaluatorGroup to use when creating evaluators.

Returns:

The fully configured TargetedSegmentListOperatorEvaluator.

addPerturbedFunctionEvaluationEvent

public final void addPerturbedFunctionEvaluationEvent(EventHandler<SolverFunctionEvaluatedEventArgs> value)

An event that gets raised when a perturbed orbit is computed. This event will be raised in whatever thread the orbit was run in.

removePerturbedFunctionEvaluationEvent

public final void removePerturbedFunctionEvaluationEvent(EventHandler<SolverFunctionEvaluatedEventArgs> value)

An event that gets raised when a perturbed orbit is computed. This event will be raised in whatever thread the orbit was run in.

addNormalFunctionEvaluationEvent

public final void addNormalFunctionEvaluationEvent(EventHandler<SolverFunctionEvaluatedEventArgs> value)

An event that gets raised when the nominal orbit is evaluated with no perturbations. This event will be raised in whatever thread the orbit was run in.

removeNormalFunctionEvaluationEvent

public final void removeNormalFunctionEvaluationEvent(EventHandler<SolverFunctionEvaluatedEventArgs> value)

An event that gets raised when the nominal orbit is evaluated with no perturbations. This event will be raised in whatever thread the orbit was run in.