Package weka.core

Class Stopwords

java.lang.Object

weka.core.Stopwords

All Implemented Interfaces:

RevisionHandler

public class Stopwords
extends Object
implements RevisionHandler

Class that can test whether a given string is a stop word. Lowercases all words before the test.

The format for reading and writing is one word per line, lines starting with '#' are interpreted as comments and therefore skipped.

The default stopwords are based on Rainbow.

Accepts the following parameter:

-i file
loads the stopwords from the given file

-o file
saves the stopwords to the given file

-p
outputs the current stopwords on stdout

Any additional parameters are interpreted as words to test as stopwords.

Version:

$Revision$

Author:

Eibe Frank (eibe@cs.waikato.ac.nz), Ashraf M. Kibriya (amk14@cs.waikato.ac.nz), FracPete (fracpete at waikato dot ac dot nz)

Constructor Summary

Constructors

Constructor	Description
Stopwords()	initializes the stopwords (based on Rainbow).

Method Summary

Modifier and Type	Method	Description
void	add(String word)	adds the given word to the stopword list (is automatically converted to lower case and trimmed)
void	clear()	removes all stopwords
Enumeration<String>	elements()	Returns a sorted enumeration over all stored stopwords
String	getRevision()	Returns the revision string.
boolean	is(String word)	Returns true if the given string is a stop word.
static boolean	isStopword(String str)	Returns true if the given string is a stop word.
static void	main(String[] args)	Accepts the following parameter:
void	read(BufferedReader reader)	Generates a new Stopwords object from the reader.
void	read(File file)	Generates a new Stopwords object from the given file
void	read(String filename)	Generates a new Stopwords object from the given file
boolean	remove(String word)	removes the word from the stopword list
String	toString()	returns the current stopwords in a string
void	write(BufferedWriter writer)	Writes the current stopwords to the given writer.
void	write(File file)	Writes the current stopwords to the given file
void	write(String filename)	Writes the current stopwords to the given file

Methods inherited from class java.lang.Object

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

Constructor Detail

Stopwords

public Stopwords()

initializes the stopwords (based on Rainbow).

Method Detail

clear

public void clear()

removes all stopwords

add

public void add(String word)

adds the given word to the stopword list (is automatically converted to lower case and trimmed)

Parameters:

word - the word to add

remove

public boolean remove(String word)

removes the word from the stopword list

Parameters:

word - the word to remove

Returns:

true if the word was found in the list and then removed

is

public boolean is(String word)

Returns true if the given string is a stop word.

Parameters:

word - the word to test

Returns:

true if the word is a stopword

elements

public Enumeration<String> elements()

Returns a sorted enumeration over all stored stopwords

Returns:

the enumeration over all stopwords

read

public void read(String filename)
          throws Exception

Generates a new Stopwords object from the given file

Parameters:

filename - the file to read the stopwords from

Throws:

Exception - if reading fails

read

public void read(File file)
          throws Exception

Generates a new Stopwords object from the given file

Parameters:

file - the file to read the stopwords from

Throws:

Exception - if reading fails

read

public void read(BufferedReader reader)
          throws Exception

Generates a new Stopwords object from the reader. The reader is closed automatically.

Parameters:

reader - the reader to get the stopwords from

Throws:

Exception - if reading fails

write

public void write(String filename)
           throws Exception

Writes the current stopwords to the given file

Parameters:

filename - the file to write the stopwords to

Throws:

Exception - if writing fails

write

public void write(File file)
           throws Exception

Writes the current stopwords to the given file

Parameters:

file - the file to write the stopwords to

Throws:

Exception - if writing fails

write

public void write(BufferedWriter writer)
           throws Exception

Writes the current stopwords to the given writer. The writer is closed automatically.

Parameters:

writer - the writer to get the stopwords from

Throws:

Exception - if writing fails

toString

public String toString()

returns the current stopwords in a string

Overrides:

toString in class Object

Returns:

the current stopwords

isStopword

public static boolean isStopword(String str)

Returns true if the given string is a stop word.

Parameters:

str - the word to test

Returns:

true if the word is a stopword

getRevision

public String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision

main

public static void main(String[] args)
                 throws Exception

Accepts the following parameter:

-i file
loads the stopwords from the given file

-o file
saves the stopwords to the given file

-p
outputs the current stopwords on stdout

Any additional parameters are interpreted as words to test as stopwords.

Parameters:

args - commandline parameters

Throws:

Exception - if something goes wrong