smile.nlp.stemmer

Class LancasterStemmer

java.lang.Object

smile.nlp.stemmer.LancasterStemmer

All Implemented Interfaces:

Stemmer

public class LancasterStemmer
extends java.lang.Object
implements Stemmer

The Paice/Husk Lancaster stemming algorithm. The stemmer is a conflation based iterative stemmer. The stemmer, although remaining efficient and easily implemented, is known to be very strong and aggressive. The stemmer utilizes a single table of rules, each of which may specify the removal or replacement of an ending. For details, see

Paice, Another stemmer, SIGIR Forum, 24(3), 56-61, 1990.

http://www.comp.lancs.ac.uk/computing/research/stemming/Links/paice.htm

Constructor Summary

Constructors

Constructor and Description
LancasterStemmer() Constructor with default rules.
LancasterStemmer(boolean stripPrefix) Constructor with default rules.
LancasterStemmer(java.io.InputStream customizedRules) Constructor with customized rules.
LancasterStemmer(java.io.InputStream customizedRules, boolean stripPrefix) Constructor with customized rules.

Method Summary

Modifier and Type	Method and Description
java.lang.String	stem(java.lang.String word) Transforms a word into its root form.

Methods inherited from class java.lang.Object

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

Constructor Detail

LancasterStemmer

public LancasterStemmer()

Constructor with default rules. By default, the stemmer will not strip prefix from words.

LancasterStemmer

public LancasterStemmer(boolean stripPrefix)

Constructor with default rules.

Parameters:

stripPrefix - true if the stemmer will strip prefix such as kilo, micro, milli, intra, ultra, mega, nano, pico, pseudo.

LancasterStemmer

public LancasterStemmer(java.io.InputStream customizedRules)
                 throws java.io.IOException

Constructor with customized rules. By default, the stemmer will not strip prefix from words.

Parameters:

customizedRules - an input stream to read customized rules.

Throws:

java.io.IOException

LancasterStemmer

public LancasterStemmer(java.io.InputStream customizedRules,
                        boolean stripPrefix)
                 throws java.io.IOException

Constructor with customized rules.

Parameters:

customizedRules - an input stream to read customized rules.

stripPrefix - true if the stemmer will strip prefix such as kilo, micro, milli, intra, ultra, mega, nano, pico, pseudo.

Throws:

java.io.IOException

Method Detail

stem

public java.lang.String stem(java.lang.String word)

Description copied from interface: Stemmer

Transforms a word into its root form.

Specified by:

stem in interface Stemmer