Package opennlp.tools.lemmatizer

Class LemmatizerME

java.lang.Object

opennlp.tools.lemmatizer.LemmatizerME

All Implemented Interfaces:

Lemmatizer

public class LemmatizerME
extends Object
implements Lemmatizer

A probabilistic lemmatizer. Tries to predict the induced permutation class for each word depending on its surrounding context. Based on Grzegorz Chrupała. 2008. Towards a Machine-Learning Architecture for Lexical Functional Grammar Parsing. PhD dissertation, Dublin City University. http://grzegorz.chrupala.me/papers/phd-single.pdf

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_BEAM_SIZE
static int	LEMMA_NUMBER

Constructor Summary

Constructors

Constructor	Description
LemmatizerME(LemmatizerModel model)	Initializes the current instance with the provided model and the default beam size of 3.

Method Summary

Modifier and Type	Method	Description
static String[]	decodeLemmas(String[] toks, String[] preds)	Decodes the lemma from the word and the induced lemma class.
static String[]	encodeLemmas(String[] toks, String[] lemmas)
String[]	lemmatize(String[] toks, String[] tags)	Generates lemmas for the word and postag returning the result in an array.
List<List<String>>	lemmatize(List<String> toks, List<String> tags)	Generates a lemma tags for the word and postag returning the result in a list of every possible lemma for each token and postag.
String[][]	predictLemmas(int numLemmas, String[] toks, String[] tags)	Predict all possible lemmas (using a default upper bound).
String[]	predictSES(String[] toks, String[] tags)	Predict Short Edit Script (automatically induced lemma class).
double[]	probs()	Returns an array with the probabilities of the last decoded sequence.
void	probs(double[] probs)	Populates the specified array with the probabilities of the last decoded sequence.
Sequence[]	topKLemmaClasses(String[] sentence, String[] tags)
Sequence[]	topKLemmaClasses(String[] sentence, String[] tags, double minSequenceScore)
Sequence[]	topKSequences(String[] sentence, String[] tags)
Sequence[]	topKSequences(String[] sentence, String[] tags, double minSequenceScore)
static LemmatizerModel	train(String languageCode, ObjectStream<LemmaSample> samples, TrainingParameters trainParams, LemmatizerFactory posFactory)

Methods inherited from class java.lang.Object

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

Field Detail

LEMMA_NUMBER

public static final int LEMMA_NUMBER

See Also:

Constant Field Values

DEFAULT_BEAM_SIZE

public static final int DEFAULT_BEAM_SIZE

See Also:

Constant Field Values

Constructor Detail

LemmatizerME

public LemmatizerME(LemmatizerModel model)

Initializes the current instance with the provided model and the default beam size of 3.

Parameters:

model - the model

Method Detail

lemmatize

public String[] lemmatize(String[] toks,
                          String[] tags)

Description copied from interface: Lemmatizer

Generates lemmas for the word and postag returning the result in an array.

Specified by:

lemmatize in interface Lemmatizer

Parameters:

toks - an array of the tokens

tags - an array of the pos tags

Returns:

an array of possible lemmas for each token in the sequence.

lemmatize

public List<List<String>> lemmatize(List<String> toks,
                                    List<String> tags)

Description copied from interface: Lemmatizer

Generates a lemma tags for the word and postag returning the result in a list of every possible lemma for each token and postag.

Specified by:

lemmatize in interface Lemmatizer

Parameters:

toks - an array of the tokens

tags - an array of the pos tags

Returns:

a list of every possible lemma for each token in the sequence.

predictSES

public String[] predictSES(String[] toks,
                           String[] tags)

Predict Short Edit Script (automatically induced lemma class).

Parameters:

toks - the array of tokens

tags - the array of pos tags

Returns:

an array containing the lemma classes

predictLemmas

public String[][] predictLemmas(int numLemmas,
                                String[] toks,
                                String[] tags)

Predict all possible lemmas (using a default upper bound).

Parameters:

numLemmas - the default number of lemmas

toks - the tokens

tags - the postags

Returns:

a double array containing all posible lemmas for each token and postag pair

decodeLemmas

public static String[] decodeLemmas(String[] toks,
                                    String[] preds)

Decodes the lemma from the word and the induced lemma class.

Parameters:

toks - the array of tokens

preds - the predicted lemma classes

Returns:

the array of decoded lemmas

encodeLemmas

public static String[] encodeLemmas(String[] toks,
                                    String[] lemmas)

topKSequences

public Sequence[] topKSequences(String[] sentence,
                                String[] tags)

topKSequences

public Sequence[] topKSequences(String[] sentence,
                                String[] tags,
                                double minSequenceScore)

probs

public void probs(double[] probs)

Populates the specified array with the probabilities of the last decoded sequence. The sequence was determined based on the previous call to lemmatize. The specified array should be at least as large as the number of tokens in the previous call to lemmatize.

Parameters:

probs - An array used to hold the probabilities of the last decoded sequence.

probs

public double[] probs()

Returns an array with the probabilities of the last decoded sequence. The sequence was determined based on the previous call to chunk.

Returns:

An array with the same number of probabilities as tokens were sent to chunk when it was last called.

train

public static LemmatizerModel train(String languageCode,
                                    ObjectStream<LemmaSample> samples,
                                    TrainingParameters trainParams,
                                    LemmatizerFactory posFactory)
                             throws IOException

Throws:

IOException

topKLemmaClasses

public Sequence[] topKLemmaClasses(String[] sentence,
                                   String[] tags)

topKLemmaClasses

public Sequence[] topKLemmaClasses(String[] sentence,
                                   String[] tags,
                                   double minSequenceScore)