Package opennlp.tools.chunker
Class DefaultChunkerContextGenerator
java.lang.Object
opennlp.tools.chunker.DefaultChunkerContextGenerator
- All Implemented Interfaces:
ChunkerContextGenerator,BeamSearchContextGenerator<TokenTag>
Features based on chunking model described in Fei Sha and Fernando Pereira. Shallow
parsing with conditional random fields. In Proceedings of HLT-NAACL 2003. Association
for Computational Linguistics, 2003.
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionString[]getContext(int i, String[] toks, String[] tags, String[] preds) Retrieves the contexts for chunking of the specifiedidx.String[]getContext(int index, TokenTag[] sequence, String[] priorDecisions, Object[] additionalContext) Returns the context for the specified position in the specifiedsequence(list).
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Constructor Details
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DefaultChunkerContextGenerator
public DefaultChunkerContextGenerator()Initializes aDefaultChunkerContextGeneratorinstance.
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Method Details
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getContext
Description copied from interface:ChunkerContextGeneratorRetrieves the contexts for chunking of the specifiedidx.- Specified by:
getContextin interfaceChunkerContextGenerator- Parameters:
i- The index of the token in the specifiedtoksarray for which the context should be constructed.toks- The tokens of the sentence. ThetoStringmethods of these objects should return the token text.tags- The POS tags for the specified tokens.preds- The previous decisions made in the tagging of this sequence. Only indices less thanidxwill be examined.- Returns:
- An array of predictive contexts on which a model basis its decisions.
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getContext
public String[] getContext(int index, TokenTag[] sequence, String[] priorDecisions, Object[] additionalContext) Description copied from interface:BeamSearchContextGeneratorReturns the context for the specified position in the specifiedsequence(list).- Specified by:
getContextin interfaceBeamSearchContextGenerator<TokenTag>- Parameters:
index- The index of thesequence.sequence- The sequence ofitemsover which the beam search is performed.priorDecisions- The sequence of decisions made prior to the context for which this decision is being made.additionalContext- Any additional context specific to a class implementing this interface.- Returns:
- The context for the specified
indexin the specifiedsequence.
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