agi.foundation.geometry

(agi.foundation.core-2024r3.jar)

Class VectorDerivative

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.geometry.Vector

agi.foundation.geometry.VectorDerivative

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IServiceProvider

public class VectorDerivative
extends Vector

A Vector (get / set) representing the derivative of the specified Order (get / set) of a given Vector (get / set) derived in a given Axes (get / set). Be careful when observing this vector in different Axes (get / set) as GeometryTransformer and KinematicTransformation assume that the zeroth order of a vector corresponds to a heading or other similar value, not the rate of another instance. The resulting values will not properly account for the dynamics of the relative rotation of the two axes. To obtain the derivative represented in a different axes, create a new instance defined in a different axes.

Constructor Summary

Constructors

Modifier	Constructor and Description
	VectorDerivative() Initializes a new instance.
protected	VectorDerivative(VectorDerivative existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
	VectorDerivative(Vector vector, int order, Axes axes) Initializes a new instance of the VectorVelocity class to represent the velocity of a given point in a given reference frame.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(Vector other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(VectorDerivative 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.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
Axes	getAxes() Gets the axes.
VectorEvaluator	getEvaluator(EvaluatorGroup group) Gets an evaluator that can be used to find the Motion<Cartesian> representing the derivative of the given Vector (get / set) in the given Axes (get / set) at the specified Order (get / set) at a given JulianDate.
int	getOrder() Gets the order.
Vector	getVector() Gets the vector.
void	setAxes(Axes value) Sets the axes.
void	setOrder(int value) Sets the order.
void	setVector(Vector value) Sets the vector.

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

VectorDerivative

public VectorDerivative()

Initializes a new instance. The user must set Vector (get / set) and Axes (get / set); Order (get / set) is set to 0 by default.

VectorDerivative

public VectorDerivative(Vector vector,
                        int order,
                        Axes axes)

Initializes a new instance of the VectorVelocity class to represent the velocity of a given point in a given reference frame.

Parameters:

vector - The original vector. The new vector will represent the derivative of this vector.

order - The order of derivative of the vector to represent with this object.

axes - The axes. The new vector will represent the derivative of the vector in this axes.

VectorDerivative

protected VectorDerivative(@Nonnull
                           VectorDerivative 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(VectorDerivative 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 VectorDerivative.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.

getVector

public final Vector getVector()

Gets the vector. This VectorDerivative will represent the derivative of the vector represented by this property.

setVector

public final void setVector(Vector value)

Sets the vector. This VectorDerivative will represent the derivative of the vector represented by this property.

getAxes

public final Axes getAxes()

Gets the axes. The vector will represent the derivative of the vector in this axes.

setAxes

public final void setAxes(Axes value)

Sets the axes. The vector will represent the derivative of the vector in this axes.

getOrder

public final int getOrder()

Gets the order. The order of the derivative this object will represent will be equal to this value.

setOrder

public final void setOrder(int value)

Sets the order. The order of the derivative this object will represent will be equal to this value.

getEvaluator

public VectorEvaluator getEvaluator(EvaluatorGroup group)

Gets an evaluator that can be used to find the Motion<Cartesian> representing the derivative of the given Vector (get / set) in the given Axes (get / set) at the specified Order (get / set) at a given JulianDate. This evaluator throws a DataUnavailableException if Vector (get / set) cannot provide enough derivative information.

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:

PropertyInvalidException - Thrown when Vector (get / set) or Axes (get / set) is null, or if Order (get / set) is less than zero.