Package org.apache.lucene.search.similarities

Class AfterEffect

java.lang.Object
org.apache.lucene.search.similarities.AfterEffect
Direct Known Subclasses:
AfterEffect.NoAfterEffect, AfterEffectB, AfterEffectL
public abstract class AfterEffect extends Object
This class acts as the base class for the implementations of the first normalization of the informative content in the DFR framework. This component is also called the after effect and is defined by the formula Inf2 = 1 - Prob2, where Prob2 measures the information gain.
See Also:

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static final class 
    AfterEffect.NoAfterEffect
    Implementation used when there is no aftereffect.

  • Constructor Summary

    Constructors
    Constructor
    Description
    AfterEffect()
    Sole constructor.

  • Method Summary

    Modifier and Type
    Method
    Description
    abstract Explanation
    explain(BasicStats stats, float tfn)
    Returns an explanation for the score.
    abstract float
    score(BasicStats stats, float tfn)
    Returns the aftereffect score.
    abstract String
    toString()
    Subclasses must override this method to return the code of the after effect formula.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • AfterEffect

      public AfterEffect()
      Sole constructor. (For invocation by subclass constructors, typically implicit.)

  • Method Details

    • score

      public abstract float score(BasicStats stats, float tfn)
      Returns the aftereffect score.

    • explain

      public abstract Explanation explain(BasicStats stats, float tfn)
      Returns an explanation for the score.

    • toString

      public abstract String toString()
      Subclasses must override this method to return the code of the after effect formula. Refer to the original paper for the list.
      Overrides:
      toString in class Object