agi.foundation.stoppingconditions

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

Class DelegateStoppingCondition

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.stoppingconditions.StoppingCondition

agi.foundation.stoppingconditions.DelegateStoppingCondition

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

public class DelegateStoppingCondition
extends StoppingCondition

A stopping condition that will stop a function by search for thresholds and extrema from values of a ConditionCheckCallback.

Constructor Summary

Constructors

Modifier	Constructor and Description
	DelegateStoppingCondition() Initializes a new instance.
	DelegateStoppingCondition(ConditionCheckCallback callback, double threshold, double valueTolerance, StopType type) Initializes a new instance.
	DelegateStoppingCondition(ConditionCheckCallback callback, double valueTolerance, StopType type) Initializes a new instance.
protected	DelegateStoppingCondition(DelegateStoppingCondition 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(DelegateStoppingCondition other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(StoppingCondition 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.
ValueDefinition<Double>	createDoubleThreshold() Creates a ValueDefinition of type double.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
ConditionCheckCallback	getCallback() Gets the ConditionCheckCallback.
StoppingConditionEvaluator	getEvaluator(EvaluatorGroup group) Gets a StoppingConditionEvaluator for use in the NumericalPropagator.
InitializeCallback	getInitializeConditionCallback() Gets a delegate to initialize this condition with the initial state.
ValueDefinition<Double>	getThreshold() Gets the threshold to stop at.
void	setCallback(ConditionCheckCallback value) Sets the ConditionCheckCallback.
void	setInitializeConditionCallback(InitializeCallback value) Sets a delegate to initialize this condition with the initial state.
void	setThreshold(ValueDefinition<Double> value) Sets the threshold to stop at.

Methods inherited from class agi.foundation.stoppingconditions.StoppingCondition

checkForSameDefinition, freezeAggregatedObjects, getAngularSetting, getConstraints, getEnabled, getFunctionTolerance, getName, getRequireFunctionTolerance, getSatisfiedCallback, getStopOnEventNumber, getTypeOfStoppingCondition, setAngularSetting, setEnabled, setFunctionTolerance, setName, setRequireFunctionTolerance, setSatisfiedCallback, setStopOnEventNumber, setTypeOfStoppingCondition, 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

DelegateStoppingCondition

public DelegateStoppingCondition()

Initializes a new instance. By default the Threshold (get / set) is set to 0 and the TypeOfStoppingCondition (get / set) is set to StopType.ANY_THRESHOLD. At a minimum, the FunctionTolerance (get / set) and Callback (get / set) must be set.

DelegateStoppingCondition

public DelegateStoppingCondition(ConditionCheckCallback callback,
                                 double valueTolerance,
                                 @Nonnull
                                 StopType type)

Initializes a new instance.

Parameters:

valueTolerance - The tolerance between the value returned by Callback (get / set) and the Threshold (get / set).

type - Specifies what type of threshold or extrema this StoppingCondition is attempting to stop on.

callback - The ConditionCheckCallback that will provide values to sample.

DelegateStoppingCondition

public DelegateStoppingCondition(ConditionCheckCallback callback,
                                 double threshold,
                                 double valueTolerance,
                                 @Nonnull
                                 StopType type)

Initializes a new instance.

Parameters:

threshold - The threshold to stop the function on. This value is ignored if the TypeOfStoppingCondition (get / set) is not a threshold.

valueTolerance - The tolerance between the value returned by callback and the threshold.

type - Specifies what type of threshold or extrema this StoppingCondition is attempting to find.

callback - The ConditionCheckCallback that will provide values to sample.

DelegateStoppingCondition

protected DelegateStoppingCondition(@Nonnull
                                    DelegateStoppingCondition 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(StoppingCondition 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 StoppingCondition

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(DelegateStoppingCondition 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 DelegateStoppingCondition.checkForSameDefinition(agi.foundation.stoppingconditions.StoppingCondition) method.

Overrides:

computeCurrentDefinitionHashCode in class StoppingCondition

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 StoppingCondition

Parameters:

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

getCallback

public final ConditionCheckCallback getCallback()

Gets the ConditionCheckCallback.

setCallback

public final void setCallback(ConditionCheckCallback value)

Sets the ConditionCheckCallback.

getInitializeConditionCallback

public final InitializeCallback getInitializeConditionCallback()

Gets a delegate to initialize this condition with the initial state. If computing the value that is getting sampled does not require initializing itself with the initial state of propagation, this can be null.

setInitializeConditionCallback

public final void setInitializeConditionCallback(InitializeCallback value)

Sets a delegate to initialize this condition with the initial state. If computing the value that is getting sampled does not require initializing itself with the initial state of propagation, this can be null.

getThreshold

public final ValueDefinition<Double> getThreshold()

Gets the threshold to stop at. This value is ignored if the TypeOfStoppingCondition (get / set) indicates to stop on an extrema. This ValueDefinition will be evaluated when the evaluator is initialized and that initial value will be used as the threshold for the actual root finding that the StoppablePropagator will search for.

It is possible to assign the same ValueDefinition for multiple conditions. This can be useful in cases when you have multiple propagators that you want to be in lock step.

Note that a ConstantValueDefinition can be used here when the actual threshold value is not known or must be changed at runtime.

This ValueDefinition by definition cannot vary with time.

setThreshold

public final void setThreshold(ValueDefinition<Double> value)

Sets the threshold to stop at. This value is ignored if the TypeOfStoppingCondition (get / set) indicates to stop on an extrema. This ValueDefinition will be evaluated when the evaluator is initialized and that initial value will be used as the threshold for the actual root finding that the StoppablePropagator will search for.

It is possible to assign the same ValueDefinition for multiple conditions. This can be useful in cases when you have multiple propagators that you want to be in lock step.

Note that a ConstantValueDefinition can be used here when the actual threshold value is not known or must be changed at runtime.

This ValueDefinition by definition cannot vary with time.

createDoubleThreshold

public ValueDefinition<Double> createDoubleThreshold()

Creates a ValueDefinition of type double. If the derived StoppingCondition defines its threshold to be of a different type than a double, it can use a ValueDefinition of that other type in its StoppingConditionEvaluator. However it is required that the threshold can be represented as a double and this must return such a value. If the specified StoppingCondition threshold is just a ValueDefinition of type double, that property can simply be returned here.

Specified by:

createDoubleThreshold in class StoppingCondition

Returns:

The threshold as a ValueDefinition where the type is a double.

getEvaluator

public StoppingConditionEvaluator getEvaluator(EvaluatorGroup group)

Gets a StoppingConditionEvaluator for use in the NumericalPropagator.

Derived classes should call StoppingCondition.validateProperties() to check properties owned by this base class, as well as validate their own properties.

Specified by:

getEvaluator in class StoppingCondition

Parameters:

group - The group to use to initialize any evaluators that will be used by the condition and its Constraints (get).

Returns:

An evaluator for this StoppingCondition.