agi.foundation.numericalmethods

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

Class ParameterizedDoubleVariable

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.numericalmethods.SegmentPropagatorVariable

agi.foundation.numericalmethods.ParameterizedDoubleVariable

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

public class ParameterizedDoubleVariable
extends SegmentPropagatorVariable

A variable for use with TargetedSegmentListDifferentialCorrector that will change the value of a ValueDefinition used in the computation of some value within the segment propagators getting propagated where T is a double. For example, you can set the value of a Threshold (get / set) to be the Value (get) provided in this variable, which gets modified in the differential corrector.

Note that it is possible to use the Value (get) in multiple SegmentDefinitions. If you do that, then the value computed will be changed for all of the SegmentPropagators that are propagated after, not just the Segment (get / set) specified.

Constructor Summary

Constructors

Modifier	Constructor and Description
	ParameterizedDoubleVariable() Initializes a new instance.
	ParameterizedDoubleVariable(double initialValue, double maximumStep, double perturbation, SegmentDefinition segment) Initializes a new instance with a specified initial value.
	ParameterizedDoubleVariable(double initialValue, double maximumStep, double perturbation, SegmentDefinition segment, SolverVariableScaling scaling) Initializes a new instance with a specified initial value.
protected	ParameterizedDoubleVariable(ParameterizedDoubleVariable 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(ParameterizedDoubleVariable other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(SegmentPropagatorVariable 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.
SegmentPropagatorVariableEvaluator	getEvaluator(EvaluatorGroup group) Gets a SegmentPropagatorVariableEvaluator for this variable.
double	getInitialValue() Gets the initial value to use when the Value (get) is initially evaluated.
ParameterizedValueDefinition<Double>	getValue() Gets the ValueDefinition to use that will be varied by a TargetedSegmentListOperatorEvaluator.
void	setInitialValue(double value) Sets the initial value to use when the Value (get) is initially evaluated.

Methods inherited from class agi.foundation.numericalmethods.SegmentPropagatorVariable

checkForSameDefinition, freezeAggregatedObjects, getName, getPerturbationValue, getSegment, getSettings, setName, setPerturbationValue, setSegment, setSettings, validateProperties

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, 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

ParameterizedDoubleVariable

public ParameterizedDoubleVariable()

Initializes a new instance.

Before ParameterizedDoubleVariable.getEvaluator(agi.foundation.EvaluatorGroup) can be called, PerturbationValue (get / set) and Segment (get / set) must be configured, and Settings (get / set) must be configured with a valid MaximumStep (get / set). Scaling (get / set) defaults to NoScalingOnVariable.

ParameterizedDoubleVariable

public ParameterizedDoubleVariable(double initialValue,
                                   double maximumStep,
                                   double perturbation,
                                   SegmentDefinition segment,
                                   SolverVariableScaling scaling)

Initializes a new instance with a specified initial value.

Parameters:

initialValue - The initial value to use when the Value (get) is evaluated.

maximumStep - The maximum step that this variable should take.

perturbation - The perturbation that should be used when finding the functions derivative with respect to this variable.

segment - The segment that this variable will operate on.

scaling - The type of scaling to be used on this variable.

ParameterizedDoubleVariable

public ParameterizedDoubleVariable(double initialValue,
                                   double maximumStep,
                                   double perturbation,
                                   SegmentDefinition segment)

Initializes a new instance with a specified initial value.

Parameters:

initialValue - The initial value to use when the Value (get) is evaluated.

maximumStep - The maximum step that this variable should take.

perturbation - The perturbation that should be used when finding the functions derivative with respect to this variable.

segment - The segment that this variable will operate on.

ParameterizedDoubleVariable

protected ParameterizedDoubleVariable(@Nonnull
                                      ParameterizedDoubleVariable 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(SegmentPropagatorVariable 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 SegmentPropagatorVariable

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(ParameterizedDoubleVariable 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 ParameterizedDoubleVariable.checkForSameDefinition(agi.foundation.numericalmethods.SegmentPropagatorVariable) method.

Overrides:

computeCurrentDefinitionHashCode in class SegmentPropagatorVariable

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 SegmentPropagatorVariable

Parameters:

enumerator - The enumerator that is informed of the dependencies of this object.

getValue

@Nonnull
public final ParameterizedValueDefinition<Double> getValue()

Gets the ValueDefinition to use that will be varied by a TargetedSegmentListOperatorEvaluator. Use this ValueDefinition in the place of one that you want to solve for with the TargetedSegmentListDifferentialCorrector.

Note that it is possible to use this value in multiple SegmentDefinitions. If you do that, then the value computed will be changed for all of the SegmentPropagators, not just the Segment (get / set) specified.

getInitialValue

public final double getInitialValue()

Gets the initial value to use when the Value (get) is initially evaluated. Note that this initial value is neither scaled nor cross-validated in any way relative to the values in the SolverVariableSettings. This value will not show up in the iteration results.

setInitialValue

public final void setInitialValue(double value)

Sets the initial value to use when the Value (get) is initially evaluated. Note that this initial value is neither scaled nor cross-validated in any way relative to the values in the SolverVariableSettings. This value will not show up in the iteration results.

getEvaluator

public SegmentPropagatorVariableEvaluator getEvaluator(EvaluatorGroup group)

Gets a SegmentPropagatorVariableEvaluator for this variable.

Specified by:

getEvaluator in class SegmentPropagatorVariable

Parameters:

group - The EvaluatorGroup to use to create any necessary evaluators for this variable.

Returns:

The fully configured variable evaluator.

Throws:

PropertyInvalidException - Thrown when Segment (get / set) is null, or Scaling (get / set) is null, or MaximumStep (get / set) is not greater than zero, or VariableTolerance (get / set) is negative.