edu.stanford.nlp.parser.lexparser
Class ChineseCharacterBasedLexicon

java.lang.Object
  edu.stanford.nlp.parser.lexparser.ChineseCharacterBasedLexicon

All Implemented Interfaces:

Lexicon, Serializable

public class ChineseCharacterBasedLexicon
extends Object
implements Lexicon

Author:

Galen Andrew

See Also:

Serialized Form

Field Summary

protected static NumberFormat	formatter
static PrintWriter	pw

Fields inherited from interface edu.stanford.nlp.parser.lexparser.Lexicon

BOUNDARY, BOUNDARY_TAG, UNKNOWN_WORD

Constructor Summary

ChineseCharacterBasedLexicon()

Method Summary

Distribution	getPOSDistribution()
static boolean	isForeign(String s)
boolean	isKnown(int word) Checks whether a word is in the lexicon.
boolean	isKnown(String word) Checks whether a word is in the lexicon.
static void	main(String[] args)
static void	printStats(Collection<Tree> trees)
void	readData(BufferedReader in) Read the lexicon from the BufferedReader in the format written by writeData.
Iterator	ruleIteratorByWord(int word, int loc) Get an iterator over all rules (pairs of (word, POS)) for this word.
String	sampleFrom() Samples over words regardless of POS: first samples POS, then samples word according to that POS
String	sampleFrom(String tag) Samples from the distribution over words with this POS according to the lexicon.
double	score(IntTaggedWord iTW, int loc) Get the score of this word with this tag (as an IntTaggedWord) at this loc.
void	train(Collection trees) Trains this lexicon on the Collection of trees.
void	tune(List trees)
void	writeData(Writer w) Write the lexicon in human-readable format to the Writer.

Methods inherited from class java.lang.Object

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

Field Detail

pw

public static PrintWriter pw

formatter

protected static NumberFormat formatter

Constructor Detail

ChineseCharacterBasedLexicon

public ChineseCharacterBasedLexicon()

Method Detail

printStats

public static void printStats(Collection<Tree> trees)

train

public void train(Collection trees)

Description copied from interface: Lexicon

Trains this lexicon on the Collection of trees.

Specified by:

train in interface Lexicon

getPOSDistribution

public Distribution getPOSDistribution()

isForeign

public static boolean isForeign(String s)

score

public double score(IntTaggedWord iTW,
                    int loc)

Description copied from interface: Lexicon

Get the score of this word with this tag (as an IntTaggedWord) at this loc. (Presumably an estimate of P(word | tag).)

Specified by:

score in interface Lexicon

Parameters:

iTW - An IntTaggedWord pairing a word and POS tag

loc - The position in the sentence. In the default implementation this is used only for unknown words to change their probability distribution when sentence initial

Returns:

A double valued score, usually - log P(word|tag)

sampleFrom

public String sampleFrom(String tag)

Samples from the distribution over words with this POS according to the lexicon.

Parameters:

tag - the POS of the word to sample

Returns:

a sampled word

sampleFrom

public String sampleFrom()

Samples over words regardless of POS: first samples POS, then samples word according to that POS

Returns:

a sampled word

ruleIteratorByWord

public Iterator ruleIteratorByWord(int word,
                                   int loc)

Description copied from interface: Lexicon

Get an iterator over all rules (pairs of (word, POS)) for this word.

Specified by:

ruleIteratorByWord in interface Lexicon

Parameters:

word - The word, represented as an integer in Numberer

loc - The position of the word in the sentence (counting from 0). Implementation note: The BaseLexicon class doesn't actually make use of this position information.

Returns:

An Iterator over a List ofIntTaggedWords, which pair the word with possible taggings as integer pairs. (Each can be thought of as a tag -> word rule.)

tune

public void tune(List trees)

main

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

Throws:

IOException

readData

public void readData(BufferedReader in)
              throws IOException

Description copied from interface: Lexicon

Read the lexicon from the BufferedReader in the format written by writeData. (An optional operation.)

Specified by:

readData in interface Lexicon

Parameters:

in - The BufferedReader to read from

Throws:

IOException

writeData

public void writeData(Writer w)
               throws IOException

Description copied from interface: Lexicon

Write the lexicon in human-readable format to the Writer. (An optional operation.)

Specified by:

writeData in interface Lexicon

Parameters:

w - The writer to output to

Throws:

IOException

isKnown

public boolean isKnown(int word)

Description copied from interface: Lexicon

Checks whether a word is in the lexicon.

Specified by:

isKnown in interface Lexicon

Parameters:

word - The word as an int

Returns:

Whether the word is in the lexicon

isKnown

public boolean isKnown(String word)

Description copied from interface: Lexicon

Checks whether a word is in the lexicon.

Specified by:

isKnown in interface Lexicon

Parameters:

word - The word as a String

Returns:

Whether the word is in the lexicon