agi.foundation.celestial

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

Class MagneticFieldVector

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.geometry.Vector

agi.foundation.celestial.MagneticFieldVector

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IServiceProvider

Direct Known Subclasses:

InternationalGeomagneticReferenceFieldVector, WorldMagneticModelVector

public class MagneticFieldVector
extends Vector

Represents the magnetic field vector at a TargetPoint (get / set) due to a planetary magnetic field.

Field Summary

Fields

Modifier and Type	Field and Description
static double	EarthReferenceDistance The reference distance used by the Earth-centered WorldMagneticModelVector and InternationalGeomagneticReferenceFieldVector classes.

Constructor Summary

Constructors

Modifier	Constructor and Description
	MagneticFieldVector() Initializes a new instance.
protected	MagneticFieldVector(MagneticFieldVector existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
	MagneticFieldVector(TimeIntervalCollection1<SphericalHarmonicCoefficients> initialMagneticFieldCoefficients, TimeIntervalCollection1<SphericalHarmonicCoefficients> magneticFieldCoefficientRates, Point targetPoint, double referenceDistance) Initializes a new instance.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(MagneticFieldVector other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(Vector 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.
static MagneticFieldVector	createCompositeIgrfCofAndWmmVector(String igrfFilePath, String wmmFilePath) Create a composite magnetic field vector that follows the recommended strategy of using IGRF coefficients for the past and WMM for future magnetic field predictions.
static MagneticFieldVector	createCompositeIgrfTxtAndWmmVector(String igrfFilePath, String wmmFilePath) Create a composite magnetic field vector that follows the recommended strategy of using IGRF coefficients for the past and WMM for future magnetic field predictions.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
ReferenceFrame	getDefinedInFrame() Gets the reference frame for the magnetic field.
VectorEvaluator	getEvaluator(EvaluatorGroup group) Gets an evaluator that can be used to find the Motion<Cartesian> of this vector in its parent Axes at a given JulianDate.
TimeIntervalCollection1<SphericalHarmonicCoefficients>	getInitialMagneticFieldCoefficients() Gets the collection that represents the static spherical-harmonic magnetic field coefficients that are valid at the beginning of specific time intervals.
TimeIntervalCollection1<SphericalHarmonicCoefficients>	getMagneticFieldCoefficientRates() Gets the collection that represents the rates of change of the spherical-harmonic magnetic field coefficients during specific time intervals.
double	getReferenceDistance() Gets the reference distance for the magnetic field model.
Point	getTargetPoint() Gets the point where the magnetic field vector is calculated.
void	setDefinedInFrame(ReferenceFrame value) Sets the reference frame for the magnetic field.
void	setInitialMagneticFieldCoefficients(TimeIntervalCollection1<SphericalHarmonicCoefficients> value) Sets the collection that represents the static spherical-harmonic magnetic field coefficients that are valid at the beginning of specific time intervals.
void	setMagneticFieldCoefficientRates(TimeIntervalCollection1<SphericalHarmonicCoefficients> value) Sets the collection that represents the rates of change of the spherical-harmonic magnetic field coefficients during specific time intervals.
void	setReferenceDistance(double value) Sets the reference distance for the magnetic field model.
void	setTargetPoint(Point value) Sets the point where the magnetic field vector is calculated.

Methods inherited from class agi.foundation.geometry.Vector

add, add, checkForSameDefinition, createVectorDerivative, cross, divide, divide, divide, divide, dot, getEvaluator, getScalarElement, getScalarElement, getService, multiply, multiply, multiply, multiply, multiply, multiply, subtract, subtract

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

Field Detail

EarthReferenceDistance

public static final double EarthReferenceDistance

The reference distance used by the Earth-centered WorldMagneticModelVector and InternationalGeomagneticReferenceFieldVector classes. Its value is 6371200 meters.

See Also:

Constant Field Values

Constructor Detail

MagneticFieldVector

public MagneticFieldVector()

Initializes a new instance. The InitialMagneticFieldCoefficients (get / set), MagneticFieldCoefficientRates (get / set), DefinedInFrame (get / set), TargetPoint (get / set), and ReferenceDistance (get / set) will need to be set.

MagneticFieldVector

public MagneticFieldVector(TimeIntervalCollection1<SphericalHarmonicCoefficients> initialMagneticFieldCoefficients,
                           TimeIntervalCollection1<SphericalHarmonicCoefficients> magneticFieldCoefficientRates,
                           Point targetPoint,
                           double referenceDistance)

Initializes a new instance. The DefinedInFrame (get / set) will default to the PrincipalFrame (get / set) of Earth as obtained from the current CentralBodiesFacet.

Parameters:

initialMagneticFieldCoefficients - A collection that represents the static spherical-harmonic magnetic field coefficients that are valid at the beginning of specific time intervals. These are in tesla.

magneticFieldCoefficientRates - A collection that represents the rates of change of the spherical-harmonic magnetic field coefficients during specific time intervals. These are in tesla/year.

targetPoint - The point where the magnetic field vector is calculated.

referenceDistance - The reference distance for the magnetic field model. This value is typically the average or equatorial radius of the central body in meters. For the IGRF and WMM models, this value is MagneticFieldVector.EarthReferenceDistance.

MagneticFieldVector

protected MagneticFieldVector(@Nonnull
                              MagneticFieldVector 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(Vector 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 Vector

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(@Nullable
                                         MagneticFieldVector 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 MagneticFieldVector.checkForSameDefinition(agi.foundation.geometry.Vector) method.

Overrides:

computeCurrentDefinitionHashCode in class Vector

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.

createCompositeIgrfCofAndWmmVector

@Nonnull
public static MagneticFieldVector createCompositeIgrfCofAndWmmVector(@Nonnull
                                                                               String igrfFilePath,
                                                                               @Nonnull
                                                                               String wmmFilePath)

Create a composite magnetic field vector that follows the recommended strategy of using IGRF coefficients for the past and WMM for future magnetic field predictions.

Parameters:

igrfFilePath - String file path for IGRF .COF file.

wmmFilePath - String file path for WMM file.

Returns:

A magnetic field vector that uses IGRF data for the past and WMM data for the future.

createCompositeIgrfTxtAndWmmVector

@Nonnull
public static MagneticFieldVector createCompositeIgrfTxtAndWmmVector(@Nonnull
                                                                               String igrfFilePath,
                                                                               @Nonnull
                                                                               String wmmFilePath)

Create a composite magnetic field vector that follows the recommended strategy of using IGRF coefficients for the past and WMM for future magnetic field predictions.

Parameters:

igrfFilePath - String file path for IGRF .txt file.

wmmFilePath - String file path for WMM file.

Returns:

A magnetic field vector that uses IGRF data for the past and WMM data for the future.

getDefinedInFrame

public final ReferenceFrame getDefinedInFrame()

Gets the reference frame for the magnetic field.

setDefinedInFrame

public final void setDefinedInFrame(ReferenceFrame value)

Sets the reference frame for the magnetic field.

getTargetPoint

public final Point getTargetPoint()

Gets the point where the magnetic field vector is calculated.

setTargetPoint

public final void setTargetPoint(Point value)

Sets the point where the magnetic field vector is calculated.

getInitialMagneticFieldCoefficients

public final TimeIntervalCollection1<SphericalHarmonicCoefficients> getInitialMagneticFieldCoefficients()

Gets the collection that represents the static spherical-harmonic magnetic field coefficients that are valid at the beginning of specific time intervals. These are in tesla.

setInitialMagneticFieldCoefficients

public final void setInitialMagneticFieldCoefficients(TimeIntervalCollection1<SphericalHarmonicCoefficients> value)

Sets the collection that represents the static spherical-harmonic magnetic field coefficients that are valid at the beginning of specific time intervals. These are in tesla.

getMagneticFieldCoefficientRates

public final TimeIntervalCollection1<SphericalHarmonicCoefficients> getMagneticFieldCoefficientRates()

Gets the collection that represents the rates of change of the spherical-harmonic magnetic field coefficients during specific time intervals. These are in tesla/year.

setMagneticFieldCoefficientRates

public final void setMagneticFieldCoefficientRates(TimeIntervalCollection1<SphericalHarmonicCoefficients> value)

Sets the collection that represents the rates of change of the spherical-harmonic magnetic field coefficients during specific time intervals. These are in tesla/year.

getReferenceDistance

public final double getReferenceDistance()

Gets the reference distance for the magnetic field model. This value is typically the average or equatorial radius of the CentralBody in meters. For the IGRF and WMM models, this value is MagneticFieldVector.EarthReferenceDistance.

setReferenceDistance

public final void setReferenceDistance(double value)

Sets the reference distance for the magnetic field model. This value is typically the average or equatorial radius of the CentralBody in meters. For the IGRF and WMM models, this value is MagneticFieldVector.EarthReferenceDistance.

getEvaluator

public VectorEvaluator getEvaluator(EvaluatorGroup group)

Gets an evaluator that can be used to find the Motion<Cartesian> of this vector in its parent Axes at a given JulianDate. Consider using the methods of GeometryTransformer instead of calling this method directly.

Specified by:

getEvaluator in class Vector

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 vector.

Throws:

ArgumentNullException - Thrown if the group is null.

PropertyInvalidException - Thrown if the CentralBody or TargetPoint (get / set) are null, if the InitialMagneticFieldCoefficients (get / set) are null or empty, if the MagneticFieldCoefficientRates (get / set) are null or empty, or if the ReferenceDistance (get / set) is not set to be a positive number.