weka.core.tokenizers

Class NGramTokenizer

java.lang.Object

weka.core.tokenizers.Tokenizer

weka.core.tokenizers.CharacterDelimitedTokenizer

weka.core.tokenizers.NGramTokenizer

All Implemented Interfaces:

Serializable, Enumeration, OptionHandler, RevisionHandler

public class NGramTokenizer
extends CharacterDelimitedTokenizer

Splits a string into an n-gram with min and max grams.

Valid options are:

 -delimiters <value>
  The delimiters to use
  (default ' \r\n\t.,;:'"()?!').

 -max <int>
  The max size of the Ngram (default = 3).

 -min <int>
  The min size of the Ngram (default = 1).

Version:

$Revision: 8034 $

Author:

Sebastian Germesin (sebastian.germesin@dfki.de), FracPete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
NGramTokenizer()

Method Summary

Methods

Modifier and Type	Method and Description
int	getNGramMaxSize() Gets the max N of the NGram.
int	getNGramMinSize() Gets the min N of the NGram.
String[]	getOptions() Gets the current option settings for the OptionHandler.
String	getRevision() Returns the revision string.
String	globalInfo() Returns a string describing the stemmer
boolean	hasMoreElements() returns true if there's more elements available
Enumeration	listOptions() Returns an enumeration of all the available options..
static void	main(String[] args) Runs the tokenizer with the given options and strings to tokenize.
Object	nextElement() Returns N-grams and also (N-1)-grams and ....
String	NGramMaxSizeTipText() Returns the tip text for this property.
String	NGramMinSizeTipText() Returns the tip text for this property.
void	setNGramMaxSize(int value) Sets the max size of the Ngram.
void	setNGramMinSize(int value) Sets the min size of the Ngram.
void	setOptions(String[] options) Parses a given list of options.
void	tokenize(String s) Sets the string to tokenize.

Methods inherited from class weka.core.tokenizers.CharacterDelimitedTokenizer

delimitersTipText, getDelimiters, setDelimiters

Methods inherited from class weka.core.tokenizers.Tokenizer

runTokenizer, tokenize

Methods inherited from class java.lang.Object

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

Constructor Detail

NGramTokenizer

public NGramTokenizer()

Method Detail

globalInfo

public String globalInfo()

Returns a string describing the stemmer

Specified by:

globalInfo in class Tokenizer

Returns:

a description suitable for displaying in the explorer/experimenter gui

listOptions

public Enumeration listOptions()

Returns an enumeration of all the available options..

Specified by:

listOptions in interface OptionHandler

Overrides:

listOptions in class CharacterDelimitedTokenizer

Returns:

an enumeration of all available options.

getOptions

public String[] getOptions()

Gets the current option settings for the OptionHandler.

Specified by:

getOptions in interface OptionHandler

Overrides:

getOptions in class CharacterDelimitedTokenizer

Returns:

the list of current option settings as an array of strings

setOptions

public void setOptions(String[] options)
                throws Exception

Parses a given list of options.

Valid options are:

 -delimiters <value>
  The delimiters to use
  (default ' \r\n\t.,;:'"()?!').

 -max <int>
  The max size of the Ngram (default = 3).

 -min <int>
  The min size of the Ngram (default = 1).

Specified by:

setOptions in interface OptionHandler

Overrides:

setOptions in class CharacterDelimitedTokenizer

Parameters:

options - the list of options as an array of strings

Throws:

Exception - if an option is not supported

getNGramMaxSize

public int getNGramMaxSize()

Gets the max N of the NGram.

Returns:

the size (N) of the NGram.

setNGramMaxSize

public void setNGramMaxSize(int value)

Sets the max size of the Ngram.

Parameters:

value - the size of the NGram.

NGramMaxSizeTipText

public String NGramMaxSizeTipText()

Returns the tip text for this property.

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

setNGramMinSize

public void setNGramMinSize(int value)

Sets the min size of the Ngram.

Parameters:

value - the size of the NGram.

getNGramMinSize

public int getNGramMinSize()

Gets the min N of the NGram.

Returns:

the size (N) of the NGram.

NGramMinSizeTipText

public String NGramMinSizeTipText()

Returns the tip text for this property.

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

hasMoreElements

public boolean hasMoreElements()

returns true if there's more elements available

Specified by:

hasMoreElements in interface Enumeration

Specified by:

hasMoreElements in class Tokenizer

Returns:

true if there are more elements available

nextElement

public Object nextElement()

Returns N-grams and also (N-1)-grams and .... and 1-grams.

Specified by:

nextElement in interface Enumeration

Specified by:

nextElement in class Tokenizer

Returns:

the next element

tokenize

public void tokenize(String s)

Sets the string to tokenize. Tokenization happens immediately.

Specified by:

tokenize in class Tokenizer

Parameters:

s - the string to tokenize

getRevision

public String getRevision()

Returns the revision string.

Returns:

the revision

main

public static void main(String[] args)

Runs the tokenizer with the given options and strings to tokenize. The tokens are printed to stdout.

Parameters:

args - the commandline options and strings to tokenize