Package 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:
Trainer,EventModelSequenceTrainer<Event>
Trains
models with 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.
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Field Summary
FieldsFields inherited from interface opennlp.tools.ml.EventModelSequenceTrainer
SEQUENCE_VALUE -
Constructor Summary
ConstructorsConstructorDescriptionInstantiates aSimplePerceptronSequenceTrainerwith a default configuration of training parameters. -
Method Summary
Modifier and TypeMethodDescriptiondoTrain(SequenceStream<Event> events) voidnextIteration(int iteration) trainModel(int iterations, SequenceStream<Event> sequenceStream, int cutoff, boolean useAverage) Trains aPerceptronModelwith given parameters.voidvalidate()Checks the configuredparameters.Methods inherited from class opennlp.tools.ml.AbstractEventModelSequenceTrainer
trainMethods inherited from class opennlp.tools.ml.AbstractTrainer
getAlgorithm, getCutoff, getIterations, init
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Field Details
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PERCEPTRON_SEQUENCE_VALUE
- See Also:
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Constructor Details
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SimplePerceptronSequenceTrainer
public SimplePerceptronSequenceTrainer()Instantiates aSimplePerceptronSequenceTrainerwith a default configuration of training parameters.
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Method Details
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validate
public void validate()Checks the configuredparameters. If a subclass overrides this, it should callsuper.validate();.- Overrides:
validatein classAbstractTrainer- Throws:
IllegalArgumentException- Thrown if the algorithm name is not equal to {PERCEPTRON_SEQUENCE_VALUE}.
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doTrain
- Specified by:
doTrainin classAbstractEventModelSequenceTrainer- Throws:
IOException
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trainModel
public AbstractModel trainModel(int iterations, SequenceStream<Event> sequenceStream, int cutoff, boolean useAverage) throws IOException Trains aPerceptronModelwith given parameters.- Parameters:
iterations- The number of iterations to use for training.sequenceStream- TheSequenceStream<Event>used as data input.cutoff- The {TrainingParameters.CUTOFF_PARAM} value to use for training.useAverage- Whether to use 'averaging', or not.- Returns:
- A valid, trained
perceptron model. - Throws:
IOException
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nextIteration
- Throws:
IOException
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