edu.mit.jwi.morph

Class WordnetStemmer

java.lang.Object

edu.mit.jwi.morph.SimpleStemmer

edu.mit.jwi.morph.WordnetStemmer

All Implemented Interfaces:

IStemmer

public class WordnetStemmer
extends SimpleStemmer

This stemmer adds functionality to the simple pattern-based stemmer SimpleStemmer by checking to see if possible stems are actually contained in Wordnet. If any stems are found, only these stems are returned. If no prospective stems are found, the word is considered unknown, and the result returned is the same as that of the SimpleStemmer class.

Since:

JWI 1.0

Version:

2.4.0

Author:

Mark A. Finlayson

Field Summary

Fields inherited from class edu.mit.jwi.morph.SimpleStemmer

ENDING_ch, ENDING_e, ENDING_man, ENDING_null, ENDING_s, ENDING_sh, ENDING_x, ENDING_y, ENDING_z, ruleMap, SUFFIX_ches, SUFFIX_ed, SUFFIX_er, SUFFIX_es, SUFFIX_est, SUFFIX_ful, SUFFIX_ies, SUFFIX_ing, SUFFIX_men, SUFFIX_s, SUFFIX_ses, SUFFIX_shes, SUFFIX_ss, SUFFIX_xes, SUFFIX_zes, underscore

Constructor Summary

Constructors

Constructor and Description
WordnetStemmer(IDictionary dict) Constructs a WordnetStemmer that, naturally, requires a Wordnet dictionary.

Method Summary

Modifier and Type	Method and Description
List<String>	findStems(String word, POS pos) Takes the surface form of a word, as it appears in the text, and the assigned Wordnet part of speech.
IDictionary	getDictionary() Returns the dictionary in use by the stemmer; will not return null

Methods inherited from class edu.mit.jwi.morph.SimpleStemmer

getNounCollocationRoots, getRuleMap, getVerbCollocationRoots, normalize, stripAdjectiveSuffix, stripNounSuffix, stripVerbSuffix

Methods inherited from class java.lang.Object

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

Constructor Detail

WordnetStemmer

public WordnetStemmer(IDictionary dict)

Constructs a WordnetStemmer that, naturally, requires a Wordnet dictionary.

Parameters:

dict - the dictionary to use; may not be null

Throws:

NullPointerException - if the specified dictionary is null

Since:

JWI 1.0

Method Detail

getDictionary

public IDictionary getDictionary()

Returns the dictionary in use by the stemmer; will not return null

Returns:

the dictionary in use by this stemmer

Since:

JWI 2.2.0

findStems

public List<String> findStems(String word,
                              POS pos)

Description copied from interface: IStemmer

Takes the surface form of a word, as it appears in the text, and the assigned Wordnet part of speech. The surface form may or may not contain whitespace or underscores, and may be in mixed case. The part of speech may be null, which means that all parts of speech should be considered. Returns a list of stems, in preferred order. No stem should be repeated in the list. If no stems are found, this call returns an empty list. It will never return null.

Specified by:

findStems in interface IStemmer

Overrides:

findStems in class SimpleStemmer

Parameters:

word - the surface form of which to find the stem

pos - the part of speech to find stems for; if null, find stems for all parts of speech

Returns:

the set of stems found for the surface form and part of speech combination