cTAKES 4.0 - Negation Annotators

There are several negation detector annotators included in cTAKES.

• The cTAKES 4.0 - Assertion component contains the PolarityCleartkAnalysisEngine, which is machine learning based.
• The ctakes-ytex-uima component provides the NegexAnnotator, a drop-in replacement for the original cTAKES negation annotator. The YTEX NegexAnnotator is based on the Negex source from the Java GeneralNegex package. Advantages over the original cTAKES algorithm include:
  
  • long-range negation
  • configurable pre- and post- negation triggers
• The original negation annotator is implemented using the ContextAnnotator and is described in cTAKES 4.0 - NE Contexts.