agi.foundation.geometry

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

Class ScalarFixed

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.geometry.Scalar

agi.foundation.geometry.ScalarFixed

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IPartialDifferentiable

public class ScalarFixed
extends Scalar
implements IPartialDifferentiable

A fixed scalar, representing a constant real valued function.

Constructor Summary

Constructors

Modifier	Constructor and Description
	ScalarFixed() Initializes a new instance.
	ScalarFixed(double fixedValue) Constructs a function which represents a constant real value.
protected	ScalarFixed(ScalarFixed 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(Scalar other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(ScalarFixed 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.
int	getDimension() Gets the dimension of the values produced by the object.
ScalarEvaluator	getEvaluator(EvaluatorGroup group) Gets an evaluator that represents a constant scalar value.
PartialDerivativesEvaluator	getPartialDerivativesEvaluator(List<IPartialDifferentiable> independentVariables, EvaluatorGroup group) This type does not have derivatives or partial derivatives with respect to any object with the exception of itself.
double	getValue() Gets the constant real value.
void	setValue(double value) Sets the constant real value.

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

Methods inherited from interface agi.foundation.infrastructure.IEquatableDefinition

getDefinitionHashCode, isSameDefinition

Constructor Detail

ScalarFixed

public ScalarFixed()

Initializes a new instance. Value (get / set) is initialized to zero.

ScalarFixed

public ScalarFixed(double fixedValue)

Constructs a function which represents a constant real value.

Parameters:

fixedValue - The real value.

ScalarFixed

protected ScalarFixed(@Nonnull
                      ScalarFixed 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(Scalar 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 Scalar

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(ScalarFixed 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 ScalarFixed.checkForSameDefinition(agi.foundation.geometry.Scalar) method.

Overrides:

computeCurrentDefinitionHashCode in class Scalar

Returns:

The computed hash code.

getValue

public final double getValue()

Gets the constant real value.

setValue

public final void setValue(double value)

Sets the constant real value.

getDimension

public final int getDimension()

Gets the dimension of the values produced by the object. For example, Vectors would have a dimension of three, and Scalars of one. A PartialDerivativesEvaluator created by this type will have a RowDimension (get) equal to this property, and a ColumnDimension (get) equal to the summation of the dimensions of the independent variables that this object is dependent on.

Specified by:

getDimension in interface IPartialDifferentiable

getEvaluator

public ScalarEvaluator getEvaluator(EvaluatorGroup group)

Gets an evaluator that represents a constant scalar value.

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.

Throws:

ArgumentNullException - Thrown when group is null.

getPartialDerivativesEvaluator

public final PartialDerivativesEvaluator getPartialDerivativesEvaluator(List<IPartialDifferentiable> independentVariables,
                                                                        EvaluatorGroup group)

This type does not have derivatives or partial derivatives with respect to any object with the exception of itself. Because of that the created PartialDerivativesEvaluator has a ColumnDimension (get) of zero if this ScalarFixed is not in the generalized state, and if it is in the generalized state it returns a 1x1 identity matrix.

Specified by:

getPartialDerivativesEvaluator in interface IPartialDifferentiable

Parameters:

independentVariables - The list of IPartialDifferentiable representing the independent variables that the created partial derivative evaluator calculates partials with respect to.

group - The EvaluatorGroup that will contain the created evaluator.

Returns:

The PartialDerivativesEvaluator.

Throws:

ArgumentNullException - Thrown when independentVariables or group is null.