opennlp.tools.ml.perceptron

Class SimplePerceptronSequenceTrainer

java.lang.Object

opennlp.tools.ml.AbstractTrainer

opennlp.tools.ml.AbstractEventModelSequenceTrainer

opennlp.tools.ml.perceptron.SimplePerceptronSequenceTrainer

All Implemented Interfaces:

EventModelSequenceTrainer

public class SimplePerceptronSequenceTrainer
extends AbstractEventModelSequenceTrainer

Trains models for sequences using the perceptron algorithm. Each outcome is represented as a binary perceptron classifier. This supports standard (integer) weighting as well average weighting. Sequence information is used in a simplified was to that described in: Discriminative Training Methods for Hidden Markov Models: Theory and Experiments with the Perceptron Algorithm. Michael Collins, EMNLP 2002. Specifically only updates are applied to tokens which were incorrectly tagged by a sequence tagger rather than to all feature across the sequence which differ from the training sequence.

Field Summary

Fields

Modifier and Type	Field and Description
static String	PERCEPTRON_SEQUENCE_VALUE

Fields inherited from class opennlp.tools.ml.AbstractTrainer

ALGORITHM_PARAM, CUTOFF_DEFAULT, CUTOFF_PARAM, ITERATIONS_DEFAULT, ITERATIONS_PARAM, TRAINER_TYPE_PARAM

Fields inherited from interface opennlp.tools.ml.EventModelSequenceTrainer

SEQUENCE_VALUE

Constructor Summary

Constructors

Constructor and Description
SimplePerceptronSequenceTrainer()

Method Summary

Methods

Modifier and Type	Method and Description
AbstractModel	doTrain(SequenceStream events)
boolean	isValid()
void	nextIteration(int iteration)
AbstractModel	trainModel(int iterations, SequenceStream sequenceStream, int cutoff, boolean useAverage)

Methods inherited from class opennlp.tools.ml.AbstractEventModelSequenceTrainer

train

Methods inherited from class opennlp.tools.ml.AbstractTrainer

getAlgorithm, getCutoff, getIterations, init

Methods inherited from class java.lang.Object

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

Methods inherited from interface opennlp.tools.ml.EventModelSequenceTrainer

init

Field Detail

PERCEPTRON_SEQUENCE_VALUE

public static final String PERCEPTRON_SEQUENCE_VALUE

See Also:

Constant Field Values

Constructor Detail

SimplePerceptronSequenceTrainer

public SimplePerceptronSequenceTrainer()

Method Detail

isValid

public boolean isValid()

Overrides:

isValid in class AbstractTrainer

doTrain

public AbstractModel doTrain(SequenceStream events)
                      throws IOException

Specified by:

doTrain in class AbstractEventModelSequenceTrainer

Throws:

IOException

trainModel

public AbstractModel trainModel(int iterations,
                       SequenceStream sequenceStream,
                       int cutoff,
                       boolean useAverage)
                         throws IOException

Throws:

IOException

nextIteration

public void nextIteration(int iteration)
                   throws IOException

Throws:

IOException