agi.foundation.celestial

(agi.foundation.models-2025r1.jar)

Class EquationOfEquinoxes

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.celestial.EquationOfEquinoxes

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

Direct Known Subclasses:

ClassicalEquationOfEquinoxes

public abstract class EquationOfEquinoxes
extends DefinitionalObject

Represents the equation of the equinox (also called the "nutation in right ascension" according to the Explanatory Supplement to the Astronomical Almanac) which defines the right ascension of the mean equinox with respect to the true equator and equinox.

The two primary theories of the equation of the equinoxes are the ClassicalEquationOfEquinoxes and the UpdatedEquationOfEquinoxes (get). To apply a particular theory to calculations involving the Earth, obtain an instance of the EarthCentralBody from the CentralBodiesFacet and replace the existing EquationOfEquinoxes (get / set) with a new instance.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	EquationOfEquinoxes() Initializes a new instance.
protected	EquationOfEquinoxes(EquationOfEquinoxes 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(DefinitionalObject other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected abstract boolean	checkForSameDefinition(EquationOfEquinoxes other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected int	computeCurrentDefinitionHashCode() Computes a hash code based on the current properties of this object.
MotionEvaluator1<Double>	getEquationOfTheEquinoxesEvaluator() Gets an evaluator to compute the equation of the equinoxes.
abstract MotionEvaluator1<Double>	getEquationOfTheEquinoxesEvaluator(EvaluatorGroup group) Gets an evaluator to compute the equation of the equinoxes.

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, clone, 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

EquationOfEquinoxes

protected EquationOfEquinoxes()

Initializes a new instance.

EquationOfEquinoxes

protected EquationOfEquinoxes(@Nonnull
                              EquationOfEquinoxes 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

checkForSameDefinition

protected final boolean checkForSameDefinition(DefinitionalObject 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 DefinitionalObject

Parameters:

other - The other instance to compare to this one.

Returns:

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

checkForSameDefinition

protected abstract boolean checkForSameDefinition(EquationOfEquinoxes 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 EquationOfEquinoxes.checkForSameDefinition(agi.foundation.infrastructure.DefinitionalObject) method.

Overrides:

computeCurrentDefinitionHashCode in class DefinitionalObject

Returns:

The computed hash code.

getEquationOfTheEquinoxesEvaluator

@Nonnull
public final MotionEvaluator1<Double> getEquationOfTheEquinoxesEvaluator()

Gets an evaluator to compute the equation of the equinoxes.

The result of evaluating will be a Motion<double> which represents the value of the equation of the equinoxes representing the offset between the mean and apparent equinoxes at the given JulianDate. No derivatives are provided.

The equation of the equinox uses a NutationModel and PrecessionModel defined by the instance of EarthCentralBody in the CentralBodiesFacet of the CalculationContext.

Returns:

An evaluator that evaluates the equation of the equinoxes.

getEquationOfTheEquinoxesEvaluator

@Nonnull
public abstract MotionEvaluator1<Double> getEquationOfTheEquinoxesEvaluator(@Nonnull
                                                                                      EvaluatorGroup group)

Gets an evaluator to compute the equation of the equinoxes.

The result of evaluating will be a Motion<double> which represents the value of the equation of the equinoxes representing the offset between the mean and apparent equinoxes at the given JulianDate. No derivatives are provided.

The equation of the equinox uses a NutationModel and PrecessionModel defined by the instance of EarthCentralBody in the CentralBodiesFacet of the CalculationContext.

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 that evaluates the equation of the equinoxes.