org.apache.lucene.search.similarities
Class DistributionSPL

java.lang.Object
  extended by org.apache.lucene.search.similarities.Distribution
      extended by org.apache.lucene.search.similarities.DistributionSPL

public class DistributionSPL
extends Distribution

The smoothed power-law (SPL) distribution for the information-based framework that is described in the original paper.

Unlike for DFR, the natural logarithm is used, as it is faster to compute and the original paper does not express any preference to a specific base.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Constructor Summary
DistributionSPL()
          Sole constructor: parameter-free
 
Method Summary
 float score(BasicStats stats, float tfn, float lambda)
          Computes the score.
 String toString()
          Subclasses must override this method to return the name of the distribution.
 
Methods inherited from class org.apache.lucene.search.similarities.Distribution
explain
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

DistributionSPL

public DistributionSPL()
Sole constructor: parameter-free

Method Detail

score

public final float score(BasicStats stats,
                         float tfn,
                         float lambda)
Description copied from class: Distribution
Computes the score.

Specified by:
score in class Distribution

toString

public String toString()
Description copied from class: Distribution
Subclasses must override this method to return the name of the distribution.

Specified by:
toString in class Distribution


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