## edu.stanford.nlp.tagger.maxent
Class TaggerFeature

    java.lang.Object
      edu.stanford.nlp.maxent.Feature
          edu.stanford.nlp.tagger.maxent.TaggerFeature

    public class TaggerFeature

extends Feature

Holds a Tagger Feature for the loglinear model. Tagger Features are binary valued, and indexed in a particular way.

Author:
  Kristina Toutanova

Field Summary

Fields inherited from class edu.stanford.nlp.maxent.Feature
`hashValues, indexedValues, instanceIndex, sum, valuesI`

Constructor Summary
`protected` `TaggerFeature(int start, int end, FeatureKey key, TTags ttags, TaggerExperiments domain)`
`` `TaggerFeature(TTags ttags, TaggerExperiments domain)`

Method Summary
`double` `ftilde()`
`double` `getVal(int index)` Get the value at the index-ed non zero value pair (x,y)
`double` `getVal(int x, int y)` This is rarely used because it is slower and requires initHashVals() to be called beforehand to initiallize the hashValues
`int` `getX(int index)`
`int` `getY(int index)`
`int` `getYTag()`
`int` `len()`
`void` `read(InDataStreamFile rF)`
`void` `save(OutDataStreamFile rF)`

Methods inherited from class edu.stanford.nlp.maxent.Feature
`initHashVals, isEmpty, print, print, setSum, setValue, sumValues`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### TaggerFeature

    protected TaggerFeature(int start,
                            int end,
                            FeatureKey key,
                            TTags ttags,
                            TaggerExperiments domain)

### TaggerFeature

    public TaggerFeature(TTags ttags,
                         TaggerExperiments domain)

Method Detail

### getVal

    public double getVal(int index)

  Description copied from class: `Feature`
  Get the value at the index-ed non zero value pair (x,y)

  Overrides:
    `getVal` in class `Feature`

### getY

    public int getY(int index)

  Overrides:
    `getY` in class `Feature`
  Returns:
    the outcome y of the index-th (x,y) pair

### len

    public int len()

  Overrides:
    `len` in class `Feature`

### getX

    public int getX(int index)

  Overrides:
    `getX` in class `Feature`
  Returns:
    the history x of the index-th (x,y) pair

### getYTag

    public int getYTag()

### getVal

    public double getVal(int x,
                         int y)

  Description copied from class: `Feature`
  This is rarely used because it is slower and requires initHashVals() to be called beforehand to initiallize the hashValues

  Overrides:
    `getVal` in class `Feature`

### save

    public void save(OutDataStreamFile rF)

  Overrides:
    `save` in class `Feature`

### read

    public void read(InDataStreamFile rF)

  Overrides:
    `read` in class `Feature`

### ftilde

    public double ftilde()

  Overrides:
    `ftilde` in class `Feature`
  Returns:
    the emptirical expectation of the feature

Stanford NLP Group