opennlp.tools.util.featuregen

Interface AdaptiveFeatureGenerator

All Known Implementing Classes:

AdditionalContextFeatureGenerator, AggregatedFeatureGenerator, BigramNameFeatureGenerator, BrownBigramFeatureGenerator, BrownTokenClassFeatureGenerator, BrownTokenFeatureGenerator, CachedFeatureGenerator, CharacterNgramFeatureGenerator, CustomFeatureGenerator, DictionaryFeatureGenerator, DocumentBeginFeatureGenerator, FastTokenClassFeatureGenerator, FeatureGeneratorAdapter, InSpanGenerator, OutcomePriorFeatureGenerator, PrefixFeatureGenerator, PreviousMapFeatureGenerator, PreviousTwoMapFeatureGenerator, SentenceFeatureGenerator, SuffixFeatureGenerator, TokenClassFeatureGenerator, TokenFeatureGenerator, TokenPatternFeatureGenerator, TrigramNameFeatureGenerator, WindowFeatureGenerator, WordClusterFeatureGenerator

public interface AdaptiveFeatureGenerator

An interface for generating features for name entity identification and for updating document level contexts.

Most implementors do not need the adaptive functionality of this interface, they should extend the FeatureGeneratorAdapter class instead.

Note:
Feature generation is not thread safe and a instance of a feature generator must only be called from one thread. The resources used by a feature generator are typically shared between man instances of features generators which are called from many threads and have to be thread safe. If that is not possible the FeatureGeneratorFactory must make a copy of the resource object for each feature generator instance.

See Also:

FeatureGeneratorAdapter, FeatureGeneratorFactory

Method Summary

Methods

Modifier and Type	Method and Description
void	clearAdaptiveData() Informs the feature generator that the context of the adaptive data (typically a document) is no longer valid.
void	createFeatures(List<String> features, String[] tokens, int index, String[] previousOutcomes) Adds the appropriate features for the token at the specified index with the specified array of previous outcomes to the specified list of features.
void	updateAdaptiveData(String[] tokens, String[] outcomes) Informs the feature generator that the specified tokens have been classified with the corresponding set of specified outcomes.

Method Detail

createFeatures

void createFeatures(List<String> features,
                  String[] tokens,
                  int index,
                  String[] previousOutcomes)

Adds the appropriate features for the token at the specified index with the specified array of previous outcomes to the specified list of features.

Parameters:

features - The list of features to be added to.

tokens - The tokens of the sentence or other text unit being processed.

index - The index of the token which is currently being processed.

previousOutcomes - The outcomes for the tokens prior to the specified index.

updateAdaptiveData

void updateAdaptiveData(String[] tokens,
                      String[] outcomes)

Informs the feature generator that the specified tokens have been classified with the corresponding set of specified outcomes.

Parameters:

tokens - The tokens of the sentence or other text unit which has been processed.

outcomes - The outcomes associated with the specified tokens.

clearAdaptiveData

void clearAdaptiveData()

Informs the feature generator that the context of the adaptive data (typically a document) is no longer valid.