agi.foundation.celestial

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

Class ScalarOccultationDualCone

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.geometry.Scalar

agi.foundation.celestial.ScalarOccultation

agi.foundation.celestial.ScalarOccultationDualCone

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IPartialDifferentiable

Direct Known Subclasses:

ScalarOccultationRegulatedDualCone

public class ScalarOccultationDualCone
extends ScalarOccultation
implements IPartialDifferentiable

Provides evaluators for percentage of occultation/eclipse at a position, as well as EclipseType using the dual cone shadow model.

The percentage runs from 0.0 (completely lit) to 1.0 (total eclipse).

This occultation model is much more accurate than ScalarOccultationCylindrical and is the one which should be used in most cases.

Constructor Summary

Constructors

Modifier	Constructor and Description
	ScalarOccultationDualCone() Creates a new Scalar with a VectorType (get / set) of RadiationVectorType.CORRECT_FOR_LIGHT_TIME_DELAY_AND_ABERRATION.
	ScalarOccultationDualCone(CentralBody illuminatingBody, Point targetPoint, CentralBody... occludingBodies) Creates a new Scalar from the given illuminating body, target point, and occluding bodies.
	ScalarOccultationDualCone(CentralBody illuminatingBody, Point targetPoint, Iterable<CentralBody> occludingBodies) Creates a new Scalar from the given illuminating body, target point, and occluding bodies.
protected	ScalarOccultationDualCone(ScalarOccultationDualCone existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.

Method Summary

Modifier and Type	Method and Description
protected static EclipseType	calculateEclipseType(double relAngle, double eclipseAngle, double illumAngle) Calculates the type of shadow a platform is in using a dual cone shadow model.
protected boolean	checkForSameDefinition(ScalarOccultation other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(ScalarOccultationDualCone 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.
int	getDimension() Gets the dimension of the values produced by the object.
List<Evaluator<EclipseType>>	getEclipseTypeEvaluators(EvaluatorGroup group) Gets a list of evaluators that calculate eclipse types for each eclipsing body according to the dual cone shadow model.
ScalarEvaluator	getEvaluator(EvaluatorGroup group) Gets an evaluator that calculates occultation according to the dual cone shadow model.
PartialDerivativesEvaluator	getPartialDerivativesEvaluator(List<IPartialDifferentiable> independentVariables, EvaluatorGroup group) This type does not have derivatives or partial derivatives with respect to any object except itself.
protected static double	occultation(EclipseType shadow, double relAngle, double eclipseAngle, double illumAngle, boolean useWithCorrector) Returns the fraction of light from an illuminating body that an eclipsing body is occulting based on the dual cone shadow model.

Methods inherited from class agi.foundation.celestial.ScalarOccultation

checkForSameDefinition, createEvaluatorHelper, eclipseAngles, enumerateDependencies, getEclipseTypeEvaluators, getIlluminatingBody, getInertialFrame, getOccludingBodies, getTargetPoint, getVectorType, setIlluminatingBody, setInertialFrame, setTargetPoint, setVectorType

Methods inherited from class agi.foundation.geometry.Scalar

add, add, add, add, add, checkForSameDefinition, createScalarDerivative, divide, divide, divide, divide, divide, getEvaluator, multiply, multiply, multiply, multiply, multiply, power, subtract, subtract, subtract, subtract, subtract, toScalar

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, freezeAggregatedObjects, 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

Methods inherited from interface agi.foundation.infrastructure.IEquatableDefinition

getDefinitionHashCode, isSameDefinition

Constructor Detail

ScalarOccultationDualCone

public ScalarOccultationDualCone()

Creates a new Scalar with a VectorType (get / set) of RadiationVectorType.CORRECT_FOR_LIGHT_TIME_DELAY_AND_ABERRATION. IlluminatingBody (get / set) and TargetPoint (get / set) must be set before an Evaluator is created, and generally at least one body should be added to OccludingBodies (get).

ScalarOccultationDualCone

public ScalarOccultationDualCone(CentralBody illuminatingBody,
                                 Point targetPoint,
                                 @Nonnull
                                 CentralBody... occludingBodies)

Creates a new Scalar from the given illuminating body, target point, and occluding bodies.

Parameters:

illuminatingBody - The illuminating body.

targetPoint - The target point.

occludingBodies - The occluding bodies.

ScalarOccultationDualCone

public ScalarOccultationDualCone(CentralBody illuminatingBody,
                                 Point targetPoint,
                                 @Nonnull
                                 Iterable<CentralBody> occludingBodies)

Creates a new Scalar from the given illuminating body, target point, and occluding bodies.

Parameters:

illuminatingBody - The illuminating body.

targetPoint - The target point.

occludingBodies - The occluding bodies.

ScalarOccultationDualCone

protected ScalarOccultationDualCone(@Nonnull
                                    ScalarOccultationDualCone 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(ScalarOccultation 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 ScalarOccultation

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(ScalarOccultationDualCone 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 ScalarOccultationDualCone.checkForSameDefinition(agi.foundation.celestial.ScalarOccultation) method.

Overrides:

computeCurrentDefinitionHashCode in class ScalarOccultation

Returns:

The computed hash code.

getDimension

public final int getDimension()

Gets the dimension of the values produced by the object. For example, Vectors would have a dimension of three, and Scalars of one. A PartialDerivativesEvaluator created by this type will have a RowDimension (get) equal to this property, and a ColumnDimension (get) equal to the summation of the dimensions of the independent variables that this object is dependent on.

Specified by:

getDimension in interface IPartialDifferentiable

getEvaluator

public ScalarEvaluator getEvaluator(EvaluatorGroup group)

Gets an evaluator that calculates occultation according to the dual cone shadow model. The occultation factor ranges from 0.0 (fully lit) to 1.0 (full occultation).

Specified by:

getEvaluator in class Scalar

Parameters:

group - The group with which to associate the new evaluator. By grouping evaluators that are often evaluated at the same Julian dates, common computations can be performed only once for the entire group instead of multiple times for each evaluator.

Returns:

An evaluator for this scalar.

Throws:

ArgumentNullException - Thrown when group is null.

PropertyInvalidException - Thrown when the property TargetPoint (get / set), IlluminatingBody (get / set), or OccludingBodies (get) or any of its members is null.

getEclipseTypeEvaluators

public List<Evaluator<EclipseType>> getEclipseTypeEvaluators(EvaluatorGroup group)

Gets a list of evaluators that calculate eclipse types for each eclipsing body according to the dual cone shadow model.

Specified by:

getEclipseTypeEvaluators in class ScalarOccultation

Parameters:

group - The group with which to associate the new evaluator. By grouping evaluators that are often evaluated at the same Julian dates, common computations can be performed only once for the entire group instead of multiple times for each evaluator.

Returns:

An evaluator for EclipseType.

Throws:

ArgumentNullException - Thrown when group is null.

PropertyInvalidException - Thrown when the property TargetPoint (get / set), IlluminatingBody (get / set), or OccludingBodies (get) or any of its members is null.

getPartialDerivativesEvaluator

public final PartialDerivativesEvaluator getPartialDerivativesEvaluator(List<IPartialDifferentiable> independentVariables,
                                                                        EvaluatorGroup group)

This type does not have derivatives or partial derivatives with respect to any object except itself. Because of that the created PartialDerivativesEvaluator has a ColumnDimension (get) of zero if this ScalarOccultation is not in the generalized state, and if it is in the generalized state it returns a 1x1 identity matrix.

Specified by:

getPartialDerivativesEvaluator in interface IPartialDifferentiable

Parameters:

independentVariables - The list of IPartialDifferentiable representing the independent variables that the created partial derivative evaluator calculates partials with respect to.

group - The EvaluatorGroup that will contain the created evaluator.

Returns:

The PartialDerivativesEvaluator.

calculateEclipseType

@Nonnull
protected static EclipseType calculateEclipseType(double relAngle,
                                                            double eclipseAngle,
                                                            double illumAngle)

Calculates the type of shadow a platform is in using a dual cone shadow model.

Parameters:

relAngle - The angular separation from the center of the eclipsing body to the center of the illuminating body.

eclipseAngle - The angular separation from the center to the edge of the eclipsing body.

illumAngle - The angular separation from the center to the edge of the illuminating body.

Returns:

The type of eclipse shadow on the platform.

occultation

protected static double occultation(@Nonnull
                                    EclipseType shadow,
                                    double relAngle,
                                    double eclipseAngle,
                                    double illumAngle,
                                    boolean useWithCorrector)

Returns the fraction of light from an illuminating body that an eclipsing body is occulting based on the dual cone shadow model.

Parameters:

shadow - The EclipseType of the current situation.

relAngle - The angular separation from the center of the eclipsing body to the center of the illuminating body

eclipseAngle - The angular separation from the center to the edge of the eclipsing body.

illumAngle - The angular separation from the center to the edge of the illuminating body.

useWithCorrector - This parameter specified whether this call is being made for a Scalar that is being corrected.

Returns:

The occultation, from 0.0 to 1.0.