opennlp.tools.coref.resolver
Class AbstractResolver

java.lang.Object
  opennlp.tools.coref.resolver.AbstractResolver

All Implemented Interfaces:

Resolver

Direct Known Subclasses:

MaxentResolver, PerfectResolver

public abstract class AbstractResolver
extends Object
implements Resolver

Default implementation of some methods in the Resolver interface.

Field Summary

protected CountedSet<Integer>	distances Debugging variable which holds statistics about mention distances during training.
protected int	numEntitiesBack The number of previous entities that resolver should consider.
protected int	numSentencesBack The number of sentences back this resolver should look for a referent.
protected boolean	showExclusions Debugging variable which specifies whether error output is generated if a class excludes as possibly coreferent mentions which are in-fact coreferent.

Constructor Summary

AbstractResolver(int neb)

Method Summary

protected boolean	excluded(MentionContext mention, DiscourseEntity entity) Excludes entities which you are not compatible with the entity under consideration.
protected String	featureString(MentionContext mention) Returns the string of "_" delimited tokens for the specified mention.
protected Parse	getHead(MentionContext mention) Returns the head parse for the specified mention.
protected int	getHeadIndex(MentionContext mention) Returns the index for the head word for the specified mention.
protected String	getHeadString(MentionContext mention) Returns the text of the head word for the specified mention.
protected int	getNumEntities() Returns the number of previous entities that resolver should consider.
protected int	getNumEntities(DiscourseModel dm) The number of entities that should be considered for resolution with the specified discourse model.
protected boolean	outOfRange(MentionContext mention, DiscourseEntity entity) Determines if the specified entity is too far from the specified mention to be resolved to it.
DiscourseEntity	retain(MentionContext mention, DiscourseModel dm) Uses the specified mention and discourse model to train this resolver.
void	setNumberSentencesBack(int nsb) Specifies the number of sentences back this resolver should look for a referent.
void	train() Retrains model on examples for which retain was called.

Methods inherited from class java.lang.Object

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

Methods inherited from interface opennlp.tools.coref.resolver.Resolver

canResolve, resolve

Field Detail

numEntitiesBack

protected int numEntitiesBack

The number of previous entities that resolver should consider.

showExclusions

protected boolean showExclusions

Debugging variable which specifies whether error output is generated if a class excludes as possibly coreferent mentions which are in-fact coreferent.

distances

protected CountedSet<Integer> distances

Debugging variable which holds statistics about mention distances during training.

numSentencesBack

protected int numSentencesBack

The number of sentences back this resolver should look for a referent.

Constructor Detail

AbstractResolver

public AbstractResolver(int neb)

Method Detail

getNumEntities

protected int getNumEntities()

Returns the number of previous entities that resolver should consider.

Returns:

the number of previous entities that resolver should consider.

setNumberSentencesBack

public void setNumberSentencesBack(int nsb)

Specifies the number of sentences back this resolver should look for a referent.

Parameters:

nsb - the number of sentences back this resolver should look for a referent.

getNumEntities

protected int getNumEntities(DiscourseModel dm)

The number of entities that should be considered for resolution with the specified discourse model.

Parameters:

dm - The discourse model.

Returns:

number of entities that should be considered for resolution.

getHead

protected Parse getHead(MentionContext mention)

Returns the head parse for the specified mention.

Parameters:

mention - The mention.

Returns:

the head parse for the specified mention.

getHeadIndex

protected int getHeadIndex(MentionContext mention)

Returns the index for the head word for the specified mention.

Parameters:

mention - The mention.

Returns:

the index for the head word for the specified mention.

getHeadString

protected String getHeadString(MentionContext mention)

Returns the text of the head word for the specified mention.

Parameters:

mention - The mention.

Returns:

The text of the head word for the specified mention.

outOfRange

protected boolean outOfRange(MentionContext mention,
                             DiscourseEntity entity)

Determines if the specified entity is too far from the specified mention to be resolved to it. Once an entity has been determined to be out of range subsequent entities are not considered. To skip intermediate entities @see excluded.

Parameters:

mention - The mention which is being considered.

entity - The entity to which the mention is to be resolved.

Returns:

true is the entity is in range of the mention, false otherwise.

excluded

protected boolean excluded(MentionContext mention,
                           DiscourseEntity entity)

Excludes entities which you are not compatible with the entity under consideration. The default implementation excludes entities whose last extent contains the extent under consideration. This prevents possessive pronouns from referring to the noun phrases they modify and other undesirable things.

Parameters:

mention - The mention which is being considered as referential.

entity - The entity to which the mention is to be resolved.

Returns:

true if the entity should be excluded, false otherwise.

retain

public DiscourseEntity retain(MentionContext mention,
                              DiscourseModel dm)

Description copied from interface: Resolver

Uses the specified mention and discourse model to train this resolver. All mentions sent to this method need to have their id fields set to indicate coreference relationships.

Specified by:

retain in interface Resolver

Parameters:

mention - The mention which is being used for training.

dm - the discourse model.

Returns:

the discourse entity which is referred to by the referring expression or null if no discourse entity is referenced.

featureString

protected String featureString(MentionContext mention)

Returns the string of "_" delimited tokens for the specified mention.

Parameters:

mention - The mention.

Returns:

the string of "_" delimited tokens for the specified mention.

train

public void train()
           throws IOException

Description copied from interface: Resolver

Retrains model on examples for which retain was called.

Specified by:

train in interface Resolver

Throws:

IOException