org.dllearner.core

Class AbstractCELA

java.lang.Object

org.dllearner.core.AbstractComponent

org.dllearner.core.AbstractCELA

All Implemented Interfaces:

ClassExpressionLearningAlgorithm, Component, LearningAlgorithm, StoppableLearningAlgorithm

Direct Known Subclasses:

AbstractTDTClassifier, CELOE, DisjunctiveCELA, DSTTDTClassifier, ELLearningAlgorithm, ELLearningAlgorithmDisjunctive, NaiveALLearner, OCEL, PCELOE, QTL2Disjunctive, QTL2DisjunctiveMultiThreaded

public abstract class AbstractCELA
extends AbstractComponent
implements ClassExpressionLearningAlgorithm, StoppableLearningAlgorithm

Abstract superclass of all class expression learning algorithm implementations. Includes support for anytime learning algorithms and resumable learning algorithms. Provides methods for filtering the best descriptions found by the algorithm. As results of the algorithm, you can either get only descriptions or evaluated descriptions. Evaluated descriptions have information about accuracy and example coverage associated with them. However, retrieving those may require addition reasoner queries, because the learning algorithms usually use but do not necessarily store this information. Changes (March/April 2011): Learning algorithms no longer have to use this class, but it still serves as a prototypical template for class expression learning algorithms.

Author:

Jens Lehmann

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_NR_OF_RESULTS This is the maximum number of results, which the learning algorithms are asked to store.

Constructor Summary

Constructors

Constructor and Description
AbstractCELA() Default Constructor
AbstractCELA(AbstractClassExpressionLearningProblem learningProblem, AbstractReasonerComponent reasoningService) Each learning algorithm gets a learning problem and a reasoner as input.

Method Summary

Modifier and Type	Method and Description
void	changeLearningProblem(AbstractClassExpressionLearningProblem learningProblem) Call this when you want to change the learning problem, but leave everything else as is.
void	changeReasonerComponent(AbstractReasonerComponent reasoningService) Call this when you want to change the reasoning service, but leave everything else as is.
Set<org.semanticweb.owlapi.model.OWLClass>	getAllowedConcepts()
Set<org.semanticweb.owlapi.model.OWLDataProperty>	getAllowedDataProperties()
Set<org.semanticweb.owlapi.model.OWLObjectProperty>	getAllowedObjectProperties()
org.semanticweb.owlapi.model.OWLClassExpression	getCurrentlyBestDescription()
List<org.semanticweb.owlapi.model.OWLClassExpression>	getCurrentlyBestDescriptions()
List<org.semanticweb.owlapi.model.OWLClassExpression>	getCurrentlyBestDescriptions(int nrOfDescriptions)
List<org.semanticweb.owlapi.model.OWLClassExpression>	getCurrentlyBestDescriptions(int nrOfDescriptions, boolean filterNonMinimalDescriptions)
EvaluatedDescription<? extends Score>	getCurrentlyBestEvaluatedDescription() Returns the best descriptions obtained so far.
NavigableSet<? extends EvaluatedDescription<? extends Score>>	getCurrentlyBestEvaluatedDescriptions() Returns a sorted set of the best descriptions found so far.
List<? extends EvaluatedDescription<? extends Score>>	getCurrentlyBestEvaluatedDescriptions(double accuracyThreshold) Returns a fraction of class descriptions with sufficiently high accuracy.
List<? extends EvaluatedDescription<? extends Score>>	getCurrentlyBestEvaluatedDescriptions(int nrOfDescriptions) Return the best currently found concepts up to some maximum count (no minimality filter used).
List<? extends EvaluatedDescription<? extends Score>>	getCurrentlyBestEvaluatedDescriptions(int nrOfDescriptions, double accuracyThreshold, boolean filterNonMinimalDescriptions) Returns a filtered list of currently best class descriptions.
List<? extends EvaluatedDescription<? extends Score>>	getCurrentlyBestMostGeneralEvaluatedDescriptions()
Set<org.semanticweb.owlapi.model.OWLClass>	getIgnoredConcepts()
Set<org.semanticweb.owlapi.model.OWLDataProperty>	getIgnoredDataProperties()
Set<org.semanticweb.owlapi.model.OWLObjectProperty>	getIgnoredObjectProperties()
AbstractClassExpressionLearningProblem<? extends Score>	getLearningProblem() The learning problem variable, which must be used by all learning algorithm implementations.
long	getMaxExecutionTimeInSeconds()
AbstractReasonerComponent	getReasoner() The reasoning service variable, which must be used by all learning algorithm implementations.
boolean	isRunning() Returns whether the learning algorithm is running.
boolean	isUseMinimizer()
void	setAllowedConcepts(Set<org.semanticweb.owlapi.model.OWLClass> allowedConcepts)
void	setAllowedDataProperties(Set<org.semanticweb.owlapi.model.OWLDataProperty> allowedDataProperties)
void	setAllowedObjectProperties(Set<org.semanticweb.owlapi.model.OWLObjectProperty> allowedObjectProperties)
void	setIgnoredConcepts(Set<org.semanticweb.owlapi.model.OWLClass> ignoredConcepts)
void	setIgnoredDataProperties(Set<org.semanticweb.owlapi.model.OWLDataProperty> ignoredDataProperties)
void	setIgnoredObjectProperties(Set<org.semanticweb.owlapi.model.OWLObjectProperty> ignoredObjectProperties)
void	setLearningProblem(LearningProblem learningProblem) Set the learning problem, which the algorithm should solve.
void	setMaxExecutionTime(long maxExecutionTime, TimeUnit timeUnit) Set the max.
void	setMaxExecutionTimeInSeconds(long maxExecutionTimeInSeconds) Set the max.
void	setReasoner(AbstractReasonerComponent reasoner)
void	setRenderer(org.semanticweb.owlapi.io.OWLObjectRenderer renderer)
void	setUseMinimizer(boolean useMinimizer)
void	stop() Stops the algorithm gracefully.
static Collection<Class<? extends AbstractClassExpressionLearningProblem>>	supportedLearningProblems() Returns all learning problems supported by this component.

Methods inherited from class org.dllearner.core.AbstractComponent

isInitialized

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.dllearner.core.LearningAlgorithm

start

Methods inherited from interface org.dllearner.core.Component

init

Field Detail

MAX_NR_OF_RESULTS

public static final int MAX_NR_OF_RESULTS

This is the maximum number of results, which the learning algorithms are asked to store. (Note, that algorithms are not required to store any results except the best one, so this limit is used to limit the performance cost for those which choose to store results.)

See Also:

Constant Field Values

Constructor Detail

AbstractCELA

public AbstractCELA()

Default Constructor

AbstractCELA

public AbstractCELA(AbstractClassExpressionLearningProblem learningProblem,
                    AbstractReasonerComponent reasoningService)

Each learning algorithm gets a learning problem and a reasoner as input.

Parameters:

learningProblem - The learning problem to solve.

reasoningService - The reasoner connecting to the underlying knowledge base.

Method Detail

changeLearningProblem

public void changeLearningProblem(AbstractClassExpressionLearningProblem learningProblem)

Call this when you want to change the learning problem, but leave everything else as is. Method can be used to apply a configured algorithm to different learning problems. Implementations, which do not only use the provided learning algorithm variable, must make sure that a call to this method indeed changes the learning problem.

Parameters:

learningProblem - The new learning problem.

changeReasonerComponent

public void changeReasonerComponent(AbstractReasonerComponent reasoningService)

Call this when you want to change the reasoning service, but leave everything else as is. Method can be used to use a configured algorithm with different reasoners. Implementations, which do not only use the provided reasoning service class variable, must make sure that a call to this method indeed changes the reasoning service.

Parameters:

reasoningService - The new reasoning service.

getCurrentlyBestDescription

public org.semanticweb.owlapi.model.OWLClassExpression getCurrentlyBestDescription()

Returns:

The best class OWLClassExpression found by the learning algorithm so far.

See Also:

getCurrentlyBestEvaluatedDescription()

getCurrentlyBestDescriptions

public List<org.semanticweb.owlapi.model.OWLClassExpression> getCurrentlyBestDescriptions()

Returns:

The best class descriptions found by the learning algorithm so far.

See Also:

getCurrentlyBestEvaluatedDescriptions()

getCurrentlyBestDescriptions

public List<org.semanticweb.owlapi.model.OWLClassExpression> getCurrentlyBestDescriptions(int nrOfDescriptions)

Specified by:

getCurrentlyBestDescriptions in interface ClassExpressionLearningAlgorithm

Parameters:

nrOfDescriptions - Limit for the number or returned descriptions.

Returns:

The best class descriptions found by the learning algorithm so far.

See Also:

getCurrentlyBestEvaluatedDescriptions(int)

getCurrentlyBestDescriptions

public List<org.semanticweb.owlapi.model.OWLClassExpression> getCurrentlyBestDescriptions(int nrOfDescriptions,
                                                                                          boolean filterNonMinimalDescriptions)

Parameters:

nrOfDescriptions - Limit for the number or returned descriptions.

filterNonMinimalDescriptions - Remove non-minimal descriptions (e.g. those which can be shortened to an equivalent concept) from the returned set.

Returns:

The best class descriptions found by the learning algorithm so far.

See Also:

getCurrentlyBestEvaluatedDescriptions(int,double,boolean)

getCurrentlyBestEvaluatedDescription

public EvaluatedDescription<? extends Score> getCurrentlyBestEvaluatedDescription()

Returns the best descriptions obtained so far.

Returns:

Best class class expression found so far.

getCurrentlyBestEvaluatedDescriptions

public NavigableSet<? extends EvaluatedDescription<? extends Score>> getCurrentlyBestEvaluatedDescriptions()

Returns a sorted set of the best descriptions found so far. We assume that they are ordered such that the best ones come in last. (In Java, iterators traverse a SortedSet in ascending order.)

Returns:

Best class descriptions found so far.

getCurrentlyBestEvaluatedDescriptions

public List<? extends EvaluatedDescription<? extends Score>> getCurrentlyBestEvaluatedDescriptions(int nrOfDescriptions,
                                                                                                   double accuracyThreshold,
                                                                                                   boolean filterNonMinimalDescriptions)

Returns a filtered list of currently best class descriptions.

Parameters:

nrOfDescriptions - Maximum number of restrictions. Use Integer.MAX_VALUE if you do not want this filter to be active.

accuracyThreshold - Minimum accuracy. All class descriptions with lower accuracy are disregarded. Specify a value between 0.0 and 1.0. Use 0.0 if you do not want this filter to be active.

filterNonMinimalDescriptions - If true, non-minimal descriptions are filtered, e.g. ALL r.TOP (being equivalent to TOP), male AND male (can be shortened to male). Currently, non-minimal descriptions are just skipped, i.e. they are completely omitted from the return list. Later, implementation might be changed to return shortened versions of those descriptions.

Returns:

A list of currently best class descriptions.

getCurrentlyBestEvaluatedDescriptions

public List<? extends EvaluatedDescription<? extends Score>> getCurrentlyBestEvaluatedDescriptions(int nrOfDescriptions)

Return the best currently found concepts up to some maximum count (no minimality filter used).

Specified by:

getCurrentlyBestEvaluatedDescriptions in interface ClassExpressionLearningAlgorithm

Parameters:

nrOfDescriptions - Maximum number of descriptions returned.

Returns:

Return value is getCurrentlyBestDescriptions(nrOfDescriptions, 0.0, false).

getCurrentlyBestEvaluatedDescriptions

public List<? extends EvaluatedDescription<? extends Score>> getCurrentlyBestEvaluatedDescriptions(double accuracyThreshold)

Returns a fraction of class descriptions with sufficiently high accuracy.

Parameters:

accuracyThreshold - Only return solutions with this accuracy or higher.

Returns:

Return value is getCurrentlyBestDescriptions(Integer.MAX_VALUE, accuracyThreshold, false).

getCurrentlyBestMostGeneralEvaluatedDescriptions

public List<? extends EvaluatedDescription<? extends Score>> getCurrentlyBestMostGeneralEvaluatedDescriptions()

supportedLearningProblems

public static Collection<Class<? extends AbstractClassExpressionLearningProblem>> supportedLearningProblems()

Returns all learning problems supported by this component. This can be used to indicate that, e.g. an algorithm is only suitable for positive only learning.

Returns:

All classes implementing learning problems, which are supported by this learning algorithm.

getLearningProblem

public AbstractClassExpressionLearningProblem<? extends Score> getLearningProblem()

The learning problem variable, which must be used by all learning algorithm implementations.

Specified by:

getLearningProblem in interface LearningAlgorithm

Returns:

Underlying learning problem.

setLearningProblem

@Autowired
public void setLearningProblem(LearningProblem learningProblem)

Description copied from interface: LearningAlgorithm

Set the learning problem, which the algorithm should solve.

Specified by:

setLearningProblem in interface LearningAlgorithm

Parameters:

learningProblem - The learning problem to solve.

getReasoner

public AbstractReasonerComponent getReasoner()

The reasoning service variable, which must be used by all learning algorithm implementations.

setReasoner

@Autowired
public void setReasoner(AbstractReasonerComponent reasoner)

stop

public void stop()

Description copied from interface: StoppableLearningAlgorithm

Stops the algorithm gracefully. A stopped algorithm cannot be resumed anymore. Use this method for cleanup and freeing memory.

Specified by:

stop in interface StoppableLearningAlgorithm

isRunning

public boolean isRunning()

Description copied from interface: StoppableLearningAlgorithm

Returns whether the learning algorithm is running. Implementation should use a boolean status variable in their implementations of the start and resume methods.

Specified by:

isRunning in interface StoppableLearningAlgorithm

Returns:

True if the algorithm is running, false otherwise.

getAllowedConcepts

public Set<org.semanticweb.owlapi.model.OWLClass> getAllowedConcepts()

setAllowedConcepts

public void setAllowedConcepts(Set<org.semanticweb.owlapi.model.OWLClass> allowedConcepts)

getIgnoredConcepts

public Set<org.semanticweb.owlapi.model.OWLClass> getIgnoredConcepts()

setIgnoredConcepts

public void setIgnoredConcepts(Set<org.semanticweb.owlapi.model.OWLClass> ignoredConcepts)

setAllowedObjectProperties

public void setAllowedObjectProperties(Set<org.semanticweb.owlapi.model.OWLObjectProperty> allowedObjectProperties)

Parameters:

allowedObjectProperties - the allowed object properties to set

getAllowedObjectProperties

public Set<org.semanticweb.owlapi.model.OWLObjectProperty> getAllowedObjectProperties()

Returns:

the allowed object properties

setIgnoredObjectProperties

public void setIgnoredObjectProperties(Set<org.semanticweb.owlapi.model.OWLObjectProperty> ignoredObjectProperties)

Parameters:

ignoredObjectProperties - the ignored object properties to set

getIgnoredObjectProperties

public Set<org.semanticweb.owlapi.model.OWLObjectProperty> getIgnoredObjectProperties()

Returns:

the ignored object properties

setAllowedDataProperties

public void setAllowedDataProperties(Set<org.semanticweb.owlapi.model.OWLDataProperty> allowedDataProperties)

Parameters:

allowedDataProperties - the allowed data properties to set

getAllowedDataProperties

public Set<org.semanticweb.owlapi.model.OWLDataProperty> getAllowedDataProperties()

Returns:

the allowed data properties

setIgnoredDataProperties

public void setIgnoredDataProperties(Set<org.semanticweb.owlapi.model.OWLDataProperty> ignoredDataProperties)

Parameters:

ignoredDataProperties - the ignored data properties to set

getIgnoredDataProperties

public Set<org.semanticweb.owlapi.model.OWLDataProperty> getIgnoredDataProperties()

Returns:

the ignored data properties

isUseMinimizer

public boolean isUseMinimizer()

setUseMinimizer

public void setUseMinimizer(boolean useMinimizer)

getMaxExecutionTimeInSeconds

public long getMaxExecutionTimeInSeconds()

setMaxExecutionTimeInSeconds

public void setMaxExecutionTimeInSeconds(long maxExecutionTimeInSeconds)

Set the max. execution time in seconds of the algorithm. It's expected that the algorithm will terminate gracefully.

Parameters:

maxExecutionTimeInSeconds - max. execution time in seconds

setMaxExecutionTime

public void setMaxExecutionTime(long maxExecutionTime,
                                TimeUnit timeUnit)

Set the max. execution time of the algorithm. It's expected that the algorithm will terminate gracefully.

Parameters:

maxExecutionTime - max. execution time

timeUnit - the time unit

setRenderer

public void setRenderer(org.semanticweb.owlapi.io.OWLObjectRenderer renderer)

Parameters:

renderer - the renderer of OWL objects to set