edu.stanford.nlp.wordseg

Class Gale2007ChineseSegmenterFeatureFactory<IN extends CoreLabel>

java.lang.Object

edu.stanford.nlp.sequences.FeatureFactory<IN>

edu.stanford.nlp.wordseg.Gale2007ChineseSegmenterFeatureFactory<IN>

All Implemented Interfaces:

Serializable

public class Gale2007ChineseSegmenterFeatureFactory<IN extends CoreLabel>
extends FeatureFactory<IN>

A Chinese segmenter Feature Factory for the GALE project. (Modified from the feature factory for Sighan Bakeoff 2005.)

c is Chinese character ("char"). c means current, n means next and p means previous.

Feature	Templates
	Current position clique
useWord1	CONSTANT, cc, nc, pc, pc+cc, if (As|Msr|Pk|Hk) cc+nc, pc,nc

Author:

Huihsin Tseng, Pichuan Chang, Christopher Manning

See Also:

Serialized Form

Field Summary

Fields inherited from class edu.stanford.nlp.sequences.FeatureFactory

cliqueC, cliqueCnC, cliqueCp2C, cliqueCp3C, cliqueCp4C, cliqueCp5C, cliqueCpC, cliqueCpCnC, cliqueCpCp2C, cliqueCpCp2Cp3C, cliqueCpCp2Cp3Cp4C, cliqueCpCp2Cp3Cp4Cp5C, flags, knownCliques

Constructor Summary

Constructors

Constructor and Description
Gale2007ChineseSegmenterFeatureFactory()

Method Summary

Modifier and Type	Method and Description
protected Collection<String>	featuresC(PaddedList<? extends CoreLabel> cInfo, int loc)
protected Collection<String>	featuresCnC(PaddedList<? extends CoreLabel> cInfo, int loc) For a CRF, this shouldn't be necessary, since the features duplicate those from CpC, but Huihsin found some valuable, presumably becuase it modified the regularization a bit.
protected Collection<String>	featuresCpC(PaddedList<? extends CoreLabel> cInfo, int loc)
protected Collection<String>	featuresCpCp2C(PaddedList<? extends CoreLabel> cInfo, int loc) Second order clique features
protected Collection<String>	featuresCpCp2Cp3C(PaddedList<? extends CoreLabel> cInfo, int loc)
Collection<String>	getCliqueFeatures(PaddedList<IN> cInfo, int loc, Clique clique) Extracts all the features from the input data at a certain index.
void	init(SeqClassifierFlags flags)

Methods inherited from class edu.stanford.nlp.sequences.FeatureFactory

addAllInterningAndSuffixing, getCliques, getCliques, getWord

Methods inherited from class java.lang.Object

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

Constructor Detail

Gale2007ChineseSegmenterFeatureFactory

public Gale2007ChineseSegmenterFeatureFactory()

Method Detail

init

public void init(SeqClassifierFlags flags)

Overrides:

init in class FeatureFactory<IN extends CoreLabel>

getCliqueFeatures

public Collection<String> getCliqueFeatures(PaddedList<IN> cInfo,
                                            int loc,
                                            Clique clique)

Extracts all the features from the input data at a certain index.

Specified by:

getCliqueFeatures in class FeatureFactory<IN extends CoreLabel>

Parameters:

cInfo - The complete data set as a List of WordInfo

loc - The index at which to extract features.

clique - The particular clique for which to extract features. It should be a member of the knownCliques list.

Returns:

A Collection of the features calculated for the word at the specified position in info.

featuresC

protected Collection<String> featuresC(PaddedList<? extends CoreLabel> cInfo,
                                       int loc)

featuresCpC

protected Collection<String> featuresCpC(PaddedList<? extends CoreLabel> cInfo,
                                         int loc)

featuresCnC

protected Collection<String> featuresCnC(PaddedList<? extends CoreLabel> cInfo,
                                         int loc)

For a CRF, this shouldn't be necessary, since the features duplicate those from CpC, but Huihsin found some valuable, presumably becuase it modified the regularization a bit.

Parameters:

cInfo - The list of characters

loc - Position of c in list

Returns:

Collection of String features (sparse set of boolean features

featuresCpCp2C

protected Collection<String> featuresCpCp2C(PaddedList<? extends CoreLabel> cInfo,
                                            int loc)

Second order clique features

Parameters:

cInfo - The list of characters

loc - Position of c in list

Returns:

Collection of String features (sparse set of boolean features

featuresCpCp2Cp3C

protected Collection<String> featuresCpCp2Cp3C(PaddedList<? extends CoreLabel> cInfo,
                                               int loc)