org.dllearner.algorithms
Class RandomGuesser

java.lang.Object
  org.dllearner.core.AbstractComponent
      org.dllearner.core.AbstractCELA
          org.dllearner.algorithms.RandomGuesser

All Implemented Interfaces:

ClassExpressionLearningAlgorithm, Component, LearningAlgorithm, StoppableLearningAlgorithm

public class RandomGuesser
extends AbstractCELA

This learning algorithm provides a random guessing technique to solve learning problems in description logics/OWL. Solutions of such problems are concepts, which can be viewed as trees. The algorithm takes as input the number of guesses (how many concepts to generate) and the maximum depth of the concepts/trees. Using this, it randomly creates trees by calling the "grow" method of a genetic programming algorithm. The target language is currently ALC.

Author:

Jens Lehmann

Field Summary

Fields inherited from class org.dllearner.core.AbstractCELA

MAX_NR_OF_RESULTS

Constructor Summary

RandomGuesser(AbstractLearningProblem learningProblem, AbstractReasonerComponent rs)

Method Summary

<T> void	applyConfigEntry(ConfigEntry<T> entry) Applies a configuration option to this component.
static Collection<ConfigOption<?>>	createConfigOptions()
RandomGuesserConfigurator	getConfigurator() For each component, a configurator class is generated in package org.dllearner.core.configurators using the script { org.dllearner.scripts.ConfigJavaGenerator}.
Description	getCurrentlyBestDescription()
EvaluatedDescription	getCurrentlyBestEvaluatedDescription() Returns the best descriptions obtained so far.
static String	getName()
Score	getSolutionScore()
void	init() Method to be called after the component has been configured.
boolean	isRunning() Returns whether the learning algorithm is running.
void	start() Starts the algorithm.
void	stop() Stops the algorithm gracefully.
static Collection<Class<? extends AbstractLearningProblem>>	supportedLearningProblems()

Methods inherited from class org.dllearner.core.AbstractCELA

changeLearningProblem, changeReasonerComponent, getCurrentlyBestDescriptions, getCurrentlyBestDescriptions, getCurrentlyBestDescriptions, getCurrentlyBestEvaluatedDescriptions, getCurrentlyBestEvaluatedDescriptions, getCurrentlyBestEvaluatedDescriptions, getCurrentlyBestEvaluatedDescriptions, getCurrentlyBestMostGeneralEvaluatedDescriptions

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomGuesser

public RandomGuesser(AbstractLearningProblem learningProblem,
                     AbstractReasonerComponent rs)

Method Detail

getConfigurator

public RandomGuesserConfigurator getConfigurator()

Description copied from class: AbstractComponent

For each component, a configurator class is generated in package org.dllearner.core.configurators using the script { org.dllearner.scripts.ConfigJavaGenerator}. The configurator provides set and get methods for the configuration options of a component.

Specified by:

getConfigurator in class AbstractComponent

Returns:

An object allowing to configure this component.

getName

public static String getName()

supportedLearningProblems

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

createConfigOptions

public static Collection<ConfigOption<?>> createConfigOptions()

applyConfigEntry

public <T> void applyConfigEntry(ConfigEntry<T> entry)
                      throws InvalidConfigOptionValueException

Description copied from class: AbstractComponent

Applies a configuration option to this component. Implementations of components should use option and value of the config entry to perform an action (usually setting an internal variable to an appropriate value). Since the availability of configurators, it is optional for components to implement this method. Instead of using this method to take an action based on a configuration value, components can also use the getters defined in the components configurator. Important note: Never call this method directly. All calls are done via the ComponentManager.

Type Parameters:

T - Type of the config entry (Integer, String etc.).

Parameters:

entry - A configuration entry.

Throws:

InvalidConfigOptionValueException - This exception is thrown if the value of the config entry is not valid. For instance, a config option may only accept values, which are within intervals 0.1 to 0.3 or 0.5 to 0.8. If the value is outside of those intervals, an exception is thrown. Note that many of the common cases are already caught in the constructor of ConfigEntry (for instance for a DoubleConfigOption you can specify an interval for the value). This means that, as a component developer, you often do not need to implement further validity checks.

See Also:

AbstractComponent.getConfigurator()

init

public void init()

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.

start

public void start()

Description copied from interface: LearningAlgorithm

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

getSolutionScore

public Score getSolutionScore()

getCurrentlyBestDescription

public Description getCurrentlyBestDescription()

Specified by:

getCurrentlyBestDescription in class AbstractCELA

Returns:

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

See Also:

AbstractCELA.getCurrentlyBestEvaluatedDescription()

getCurrentlyBestEvaluatedDescription

public EvaluatedDescription getCurrentlyBestEvaluatedDescription()

Description copied from class: AbstractCELA

Returns the best descriptions obtained so far.

Specified by:

getCurrentlyBestEvaluatedDescription in class AbstractCELA

Returns:

Best class description found so far.

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.

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.

Returns:

True if the algorithm is running, false otherwise.