agi.foundation.celestial

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

Class ScalarVariableAreaJulianDate

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.geometry.Scalar

agi.foundation.celestial.ScalarVariableArea

agi.foundation.celestial.ScalarVariableAreaJulianDate

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

public class ScalarVariableAreaJulianDate
extends ScalarVariableArea

A Scalar that enables interpolation of spacecraft area data to use as a reference area for AtmosphericDragForce and SimpleSolarRadiationForce.

Constructor Summary

Constructors

Modifier	Constructor and Description
	ScalarVariableAreaJulianDate(int interpolationOrder, Map<Double,Double> areaData, JulianDate epoch, boolean cycleRepeats) Initializes a new instance.
	ScalarVariableAreaJulianDate(int interpolationOrder, Map<JulianDate,Double> areaData, boolean cycleRepeats) Initializes a new instance.
protected	ScalarVariableAreaJulianDate(ScalarVariableAreaJulianDate 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(ScalarVariableArea other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(ScalarVariableAreaJulianDate 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.
Map<JulianDate,Double>	getAreaData() Gets a collection of key-value pairs with JulianDate as the key and area (in meters squared) as the value.
boolean	getCycleRepeats() Gets a value indicating whether any time outside the time interval defined by the AreaData (get) will be wrapped by adding or subtracting an integer number of time intervals until the transformed time is inside the time interval.
ScalarEvaluator	getEvaluator(EvaluatorGroup group) Gets an evaluator that can be used to find the value of this scalar function at a given JulianDate.
void	setCycleRepeats(boolean value) Sets a value indicating whether any time outside the time interval defined by the AreaData (get) will be wrapped by adding or subtracting an integer number of time intervals until the transformed time is inside the time interval.

Methods inherited from class agi.foundation.celestial.ScalarVariableArea

checkForSameDefinition, getInterpolationOrder, readFrom, readFrom, setInterpolationOrder

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, enumerateDependencies, 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

Constructor Detail

ScalarVariableAreaJulianDate

public ScalarVariableAreaJulianDate(int interpolationOrder,
                                    Map<JulianDate,Double> areaData,
                                    boolean cycleRepeats)

Initializes a new instance.

Parameters:

interpolationOrder - The order of the interpolation that will be done to estimate the area.

areaData - Collection of key-value pairs with JulianDate as the key and area (in meters squared) as the value.

cycleRepeats - If true, any time outside the time interval defined by the areaData will be wrapped by adding or subtracting an integer number of time intervals until the transformed time is inside the time interval. If false, any time that is before the time interval defined by the areaData will be set to the minimum time within the interval. Similarly, any time after that time interval will be set to the maximum time within the interval.

ScalarVariableAreaJulianDate

public ScalarVariableAreaJulianDate(int interpolationOrder,
                                    Map<Double,Double> areaData,
                                    @Nonnull
                                    JulianDate epoch,
                                    boolean cycleRepeats)

Initializes a new instance.

Parameters:

interpolationOrder - The order of the interpolation that will be done to estimate the area.

areaData - Collection of key-value pairs with seconds after epoch as the key and area (in meters squared) as the value.

epoch - The reference epoch that is used to transform the epoch seconds keys in the areaData into JulianDate keys.

cycleRepeats - If true, any time outside the time interval defined by the areaData will be wrapped by adding or subtracting an integer number of time intervals until the transformed time is inside the time interval. If false, any time that is before the time interval defined by the areaData will be set to the minimum time within the interval. Similarly, any time after that time interval will be set to the maximum time within the interval.

ScalarVariableAreaJulianDate

protected ScalarVariableAreaJulianDate(ScalarVariableAreaJulianDate existingInstance,
                                       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(ScalarVariableArea 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 ScalarVariableArea

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(ScalarVariableAreaJulianDate 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 ScalarVariableAreaJulianDate.checkForSameDefinition(agi.foundation.celestial.ScalarVariableArea) method.

Overrides:

computeCurrentDefinitionHashCode in class ScalarVariableArea

Returns:

The computed hash code.

getAreaData

public final Map<JulianDate,Double> getAreaData()

Gets a collection of key-value pairs with JulianDate as the key and area (in meters squared) as the value.

getCycleRepeats

public final boolean getCycleRepeats()

Gets a value indicating whether any time outside the time interval defined by the AreaData (get) will be wrapped by adding or subtracting an integer number of time intervals until the transformed time is inside the time interval. If false, any time that is before the time interval defined by the AreaData (get) will be set to the minimum time within the interval. Similarly, any time after that time interval will be set to the maximum time within the interval.

setCycleRepeats

public final void setCycleRepeats(boolean value)

Sets a value indicating whether any time outside the time interval defined by the AreaData (get) will be wrapped by adding or subtracting an integer number of time intervals until the transformed time is inside the time interval. If false, any time that is before the time interval defined by the AreaData (get) will be set to the minimum time within the interval. Similarly, any time after that time interval will be set to the maximum time within the interval.

getEvaluator

public ScalarEvaluator getEvaluator(EvaluatorGroup group)

Gets an evaluator that can be used to find the value of this scalar function at a given JulianDate. Adds the evaluator to the EvaluatorGroup.

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.