agi.foundation.celestial

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

Class WorldMagneticModelVector

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.geometry.Vector

agi.foundation.celestial.MagneticFieldVector

agi.foundation.celestial.WorldMagneticModelVector

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IServiceProvider

public class WorldMagneticModelVector
extends MagneticFieldVector

Represents the magnetic field vector at a TargetPoint (get / set) due to the Earth's magnetic field, as modeled by a WMM model.

See https://www.ngdc.noaa.gov/geomag/WMM/soft.shtml for more information about the WMM model.

Field Summary

Fields inherited from class agi.foundation.celestial.MagneticFieldVector

EarthReferenceDistance

Constructor Summary

Constructors

Modifier	Constructor and Description
	WorldMagneticModelVector() Initializes a new instance.
	WorldMagneticModelVector(TimeIntervalCollection1<SphericalHarmonicCoefficients> initialMagneticFieldCoefficients, TimeIntervalCollection1<SphericalHarmonicCoefficients> magneticFieldCoefficientRates) Initializes a new instance.
	WorldMagneticModelVector(TimeIntervalCollection1<SphericalHarmonicCoefficients> initialMagneticFieldCoefficients, TimeIntervalCollection1<SphericalHarmonicCoefficients> magneticFieldCoefficientRates, Point targetPoint) Initializes a new instance.
protected	WorldMagneticModelVector(WorldMagneticModelVector 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(MagneticFieldVector other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(WorldMagneticModelVector 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 WorldMagneticModelVector	readFile(BufferedReader reader) Reads a WMM file and creates a magnetic field vector from it.
static WorldMagneticModelVector	readFile(String filePath) Reads a WMM file and creates a magnetic field vector from it.

Methods inherited from class agi.foundation.celestial.MagneticFieldVector

checkForSameDefinition, createCompositeIgrfCofAndWmmVector, createCompositeIgrfTxtAndWmmVector, enumerateDependencies, getDefinedInFrame, getEvaluator, getInitialMagneticFieldCoefficients, getMagneticFieldCoefficientRates, getReferenceDistance, getTargetPoint, setDefinedInFrame, setInitialMagneticFieldCoefficients, setMagneticFieldCoefficientRates, setReferenceDistance, setTargetPoint

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

Constructor Detail

WorldMagneticModelVector

public WorldMagneticModelVector()

Initializes a new instance. The DefinedInFrame (get / set) is set to the PrincipalFrame (get / set) of Earth as obtained from the current CentralBodiesFacet. The ReferenceDistance (get / set) is set to MagneticFieldVector.EarthReferenceDistance. Typically, this constructor is not used directly. Rather, WorldMagneticModelVector.readFile(String) is used to create the IGRF magnetic field vector.

WorldMagneticModelVector

public WorldMagneticModelVector(TimeIntervalCollection1<SphericalHarmonicCoefficients> initialMagneticFieldCoefficients,
                                TimeIntervalCollection1<SphericalHarmonicCoefficients> magneticFieldCoefficientRates)

Initializes a new instance. Typically, this constructor is not used directly. Rather, WorldMagneticModelVector.readFile(String) is used to create the IGRF magnetic field vector.

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.

WorldMagneticModelVector

public WorldMagneticModelVector(TimeIntervalCollection1<SphericalHarmonicCoefficients> initialMagneticFieldCoefficients,
                                TimeIntervalCollection1<SphericalHarmonicCoefficients> magneticFieldCoefficientRates,
                                Point targetPoint)

Initializes a new instance. Typically, this constructor is not used directly. Rather, WorldMagneticModelVector.readFile(String) is used to create the IGRF magnetic field vector.

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.

WorldMagneticModelVector

protected WorldMagneticModelVector(@Nonnull
                                   WorldMagneticModelVector 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

Overrides:

clone in class MagneticFieldVector

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(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).

Overrides:

checkForSameDefinition in class MagneticFieldVector

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
                                         WorldMagneticModelVector 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 WorldMagneticModelVector.checkForSameDefinition(agi.foundation.celestial.MagneticFieldVector) method.

Overrides:

computeCurrentDefinitionHashCode in class MagneticFieldVector

Returns:

The computed hash code.

readFile

@Nonnull
public static WorldMagneticModelVector readFile(@Nonnull
                                                          String filePath)

Reads a WMM file and creates a magnetic field vector from it.

Note that the final block of the InitialMagneticFieldCoefficients (get / set) and MagneticFieldCoefficientRates (get / set) will extend indefinitely into the future. Also, note that the units of the magnetic field vector are in tesla, the TargetPoint (get / set) will still need to be set, and the magnetic field vector will be resolved in the Axes (get / set) of the PrincipalFrame (get / set) of Earth as obtained from the current CentralBodiesFacet unless the DefinedInFrame (get / set) is set. The ReferenceDistance (get / set) is set to MagneticFieldVector.EarthReferenceDistance, which is the official reference distance for the WMM models.

See WMM website: https://www.ngdc.noaa.gov/geomag/WMM/soft.shtml. An updated WMM .COF file can be found inside the WMM2020COF.zip download.

Parameters:

filePath - String file path for WMM file.

Returns:

A magnetic field vector corresponding to the WMM model.

Throws:

ArgumentNullException - Thrown when filePath passed in is null.

readFile

@Nonnull
public static WorldMagneticModelVector readFile(@Nonnull
                                                          BufferedReader reader)

Reads a WMM file and creates a magnetic field vector from it.

Note that the final block of the InitialMagneticFieldCoefficients (get / set) and MagneticFieldCoefficientRates (get / set) will extend indefinitely into the future. Also, note that the units of the magnetic field vector are in tesla, the TargetPoint (get / set) will still need to be set, and the magnetic field vector will be resolved in the Axes (get / set) of the PrincipalFrame (get / set) of Earth as obtained from the current CentralBodiesFacet unless the DefinedInFrame (get / set) is set. The ReferenceDistance (get / set) is set to MagneticFieldVector.EarthReferenceDistance, which is the official reference distance for the WMM models.

See WMM website: https://www.ngdc.noaa.gov/geomag/WMM/soft.shtml. An updated WMM .COF file can be found inside the WMM2020COF.zip download.

Parameters:

reader - BufferedReader for the .COF file to read.

Returns:

A magnetic field vector corresponding to the WMM model.

Throws:

ArgumentNullException - Thrown when reader passed in is null.