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.
-
Constructor Summary
-
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, String[] tokens, String[] postags, String[] priorDecisions, Object[] additionalContext) String[]
getContext
(int index, TokenTag[] sequence, String[] priorDecisions, Object[] additionalContext) Returns the context for the specified position in the specifiedsequence
(list).
-
Constructor Details
-
DefaultChunkerContextGenerator
public DefaultChunkerContextGenerator()Initializes aDefaultChunkerContextGenerator
instance.
-
-
Method Details
-
getContext
-
getContext
Description copied from interface:ChunkerContextGenerator
Retrieves the contexts for chunking of the specifiedidx
.- Specified by:
getContext
in interfaceChunkerContextGenerator
- Parameters:
i
- The index of the token in the specifiedtoks
array for which the context should be constructed.toks
- The tokens of the sentence. ThetoString
methods 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 thanidx
will be examined.- Returns:
- An array of predictive contexts on which a model basis its decisions.
-
getContext
public String[] getContext(int index, TokenTag[] sequence, String[] priorDecisions, Object[] additionalContext) Description copied from interface:BeamSearchContextGenerator
Returns the context for the specified position in the specifiedsequence
(list).- Specified by:
getContext
in interfaceBeamSearchContextGenerator<TokenTag>
- Parameters:
index
- The index of thesequence
.sequence
- The sequence ofitems
over 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 addition context specific to a class implementing this interface.- Returns:
- The context for the specified
index
in the specifiedsequence
.
-