org.dllearner.algorithms.el

Class ELLearningAlgorithmDisjunctive

java.lang.Object

org.dllearner.core.AbstractComponent

org.dllearner.core.AbstractCELA

org.dllearner.algorithms.el.ELLearningAlgorithmDisjunctive

All Implemented Interfaces:

ClassExpressionLearningAlgorithm, Component, LearningAlgorithm, StoppableLearningAlgorithm

public class ELLearningAlgorithmDisjunctive
extends AbstractCELA

A learning algorithm for EL, which will based on an ideal refinement operator. The algorithm learns disjunctions of EL trees as follows: - given pos. and neg. examples, noise in %, min coverage per tree x % - it searches for an EL tree, which covers at least x % of all positive examples and at most (coverage_on_positives * noise) negative examples - the covered examples are removed from the pos. and neg. examples - termination: all(?) positive examples covered ev. besser: feste Suchzeiten pro Baum => es wird dann jeweils der beste Baum gewählt => Terminierung, wenn alles gecovered ist oder kein Baum mit ausreichender Qualität in dem Zeitfenster gefunden wird In contrast to many other algorithms, only one solution is returned. Additionally, the algorithm is not really an anytime algorithm, since the solution is constructed stepwise as a set of trees. Parameter optimisation: - runtime per tree: 10 seconds - tradeoff pos/neg: 1.0 1.2 1.4 1.6. 1.8 2.0 - min score: 0 -2.5 -5 -7.5 -10 - tests: 30 - runtime per test: 200 seconds => 2000 seconds cross val => 60000 seconds overall Next idea: - reduce tradeoff for each tree added (start with 2.0 and reduce by 0.1) - for the last tress it is not very important to cover less negatives - minimum is something between 0 and -1 (ensures that in the worst case as many positives as negatives are covered) - only high impact parameter is runtime (and maybe start tradeoff)

Author:

Jens Lehmann

Field Summary

Fields inherited from class org.dllearner.core.AbstractCELA

allowedConcepts, allowedDataProperties, allowedObjectProperties, baseURI, bestEvaluatedDescriptions, dataFactory, dfPercent, duplicator, ignoredConcepts, ignoredDataProperties, ignoredObjectProperties, isRunning, learningProblem, MAX_NR_OF_RESULTS, maxExecutionTimeInSeconds, nanoStartTime, OWL_NOTHING, OWL_THING, prefixes, reasoner, renderer, stop

Fields inherited from class org.dllearner.core.AbstractComponent

initialized

Constructor Summary

Constructors

Constructor and Description
ELLearningAlgorithmDisjunctive()
ELLearningAlgorithmDisjunctive(AbstractClassExpressionLearningProblem problem, AbstractReasonerComponent reasoner)

Method Summary

Modifier and Type	Method and Description
double	getNoisePercentage()
org.semanticweb.owlapi.model.OWLClassExpression	getStartClass()
SearchTreeNode	getStartNode()
double	getTreeSearchTimeSeconds()
void	init() Method to be called after the component has been configured.
boolean	isInstanceBasedDisjoints()
boolean	isStopOnFirstDefinition()
boolean	isTryFullCoverage()
void	setInstanceBasedDisjoints(boolean instanceBasedDisjoints)
void	setNoisePercentage(double noisePercentage)
void	setStartClass(org.semanticweb.owlapi.model.OWLClassExpression startClass)
void	setStopOnFirstDefinition(boolean stopOnFirstDefinition)
void	setTreeSearchTimeSeconds(double treeSearchTimeSeconds)
void	setTryFullCoverage(boolean tryFullCoverage)
void	start() Starts the algorithm.
static Collection<Class<? extends AbstractClassExpressionLearningProblem>>	supportedLearningProblems()

Methods inherited from class org.dllearner.core.AbstractCELA

changeLearningProblem, changeReasonerComponent, descriptionToString, getAllowedConcepts, getAllowedDataProperties, getAllowedObjectProperties, getCurrentlyBestDescription, getCurrentlyBestDescriptions, getCurrentlyBestDescriptions, getCurrentlyBestDescriptions, getCurrentlyBestEvaluatedDescription, getCurrentlyBestEvaluatedDescriptions, getCurrentlyBestEvaluatedDescriptions, getCurrentlyBestEvaluatedDescriptions, getCurrentlyBestEvaluatedDescriptions, getCurrentlyBestMostGeneralEvaluatedDescriptions, getCurrentRuntimeInMilliSeconds, getDurationAsString, getIgnoredConcepts, getIgnoredDataProperties, getIgnoredObjectProperties, getLearningProblem, getMaxExecutionTimeInSeconds, getNiceDescription, getReasoner, getRemainingRuntimeInMilliseconds, getSolutionString, initClassHierarchy, initDataPropertyHierarchy, initObjectPropertyHierarchy, isRunning, isTimeExpired, isUseMinimizer, rewrite, setAllowedConcepts, setAllowedDataProperties, setAllowedObjectProperties, setIgnoredConcepts, setIgnoredDataProperties, setIgnoredObjectProperties, setLearningProblem, setMaxExecutionTime, setMaxExecutionTimeInSeconds, setReasoner, setRenderer, setUseMinimizer, stop

Methods inherited from class org.dllearner.core.AbstractComponent

isInitialized

Methods inherited from class java.lang.Object

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

Constructor Detail

ELLearningAlgorithmDisjunctive

public ELLearningAlgorithmDisjunctive()

ELLearningAlgorithmDisjunctive

public ELLearningAlgorithmDisjunctive(AbstractClassExpressionLearningProblem problem,
                                      AbstractReasonerComponent reasoner)

Method Detail

supportedLearningProblems

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

init

public void init()
          throws ComponentInitException

Description copied from interface: Component

Method to be called after the component has been configured. Implementation of components can overwrite this method to perform setup and initialisation tasks for this component.

Throws:

ComponentInitException - This exception is thrown if any exceptions occur within the initialisation process of this component. As component developer, you are encouraged to re-throw occurring exception as ComponentInitException and giving an error message as well as the actually exception by using the constructor ComponentInitException.ComponentInitException(String, Throwable).

start

public void start()

Description copied from interface: LearningAlgorithm

Starts the algorithm. It runs until paused, stopped, or a termination criterion has been reached.

getStartNode

public SearchTreeNode getStartNode()

Returns:

the startNode

getStartClass

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

setStartClass

public void setStartClass(org.semanticweb.owlapi.model.OWLClassExpression startClass)

isInstanceBasedDisjoints

public boolean isInstanceBasedDisjoints()

setInstanceBasedDisjoints

public void setInstanceBasedDisjoints(boolean instanceBasedDisjoints)

getTreeSearchTimeSeconds

public double getTreeSearchTimeSeconds()

setTreeSearchTimeSeconds

public void setTreeSearchTimeSeconds(double treeSearchTimeSeconds)

isTryFullCoverage

public boolean isTryFullCoverage()

setTryFullCoverage

public void setTryFullCoverage(boolean tryFullCoverage)

getNoisePercentage

public double getNoisePercentage()

Returns:

the estimated noise value in percentage

setNoisePercentage

public void setNoisePercentage(double noisePercentage)

Parameters:

noisePercentage - the estimated noise value in percentage to set

isStopOnFirstDefinition

public boolean isStopOnFirstDefinition()

setStopOnFirstDefinition

public void setStopOnFirstDefinition(boolean stopOnFirstDefinition)