Class DefaultChunkerContextGenerator

java.lang.Object
opennlp.tools.chunker.DefaultChunkerContextGenerator
All Implemented Interfaces:
ChunkerContextGenerator, BeamSearchContextGenerator<TokenTag>

public class DefaultChunkerContextGenerator extends Object implements ChunkerContextGenerator
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 Details

  • Method Details

    • getContext

      public String[] getContext(int index, String[] tokens, String[] postags, String[] priorDecisions, Object[] additionalContext)
    • getContext

      public String[] getContext(int i, String[] toks, String[] tags, String[] preds)
      Description copied from interface: ChunkerContextGenerator
      Retrieves the contexts for chunking of the specified idx.
      Specified by:
      getContext in interface ChunkerContextGenerator
      Parameters:
      i - The index of the token in the specified toks array for which the context should be constructed.
      toks - The tokens of the sentence. The toString 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 than idx 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 specified sequence (list).
      Specified by:
      getContext in interface BeamSearchContextGenerator<TokenTag>
      Parameters:
      index - The index of the sequence.
      sequence - The sequence of items 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 specified sequence.