HMMDecoder Example 3: Part-of-Speech Tagging - Teradata Vantage

In this example, the parts of speech correspond to the hidden states of the HMM function, A (adjective) and N (noun).

Input

• Set of phrases whose parts of speech are unknown
• Trained table of initial states, initial
• Trained table of state transitions, state_transition
• Trained table of emissions, emission

SQL Call

SELECT * FROM HMMDecoder (
  ON initial AS InitStateProb PARTITION BY model ORDER BY model, tag
  ON state_transition as TransProb PARTITION BY model
  ON emission AS EmissionProb PARTITION BY model
  ON phrases AS observation PARTITION BY model
    ORDER BY model, phrase_id ASC
  USING
  InitStateModelColumn ('model')
  InitStateColumn ('tag')
  InitStateProbColumn ('probability')
  TransAttributeColumn ('model')
  TransFromStateColumn ('from_tag')
  TransToStateColumn ('to_tag')
  TransProbColumn ('probability')
  EmitModelColumn ('model')
  EmitStateColumn ('tag')
  EmitObsColumn ('word')
  EmitProbColumn ('probability')
  ModelColumn ('model')
  SeqColumn ('phrase_id')
  ObsColumn ('word')
) AS dt ORDER by 1, 2, 3;

Output