org.apache.lucene.search.similarities
Class LambdaTTF

java.lang.Object
  extended by org.apache.lucene.search.similarities.Lambda
      extended by org.apache.lucene.search.similarities.LambdaTTF

public class LambdaTTF
extends Lambda

Computes lambda as totalTermFreq+1 / numberOfDocuments+1.

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

Constructor Summary
LambdaTTF()
          Sole constructor: parameter-free
 
Method Summary
 Explanation explain(BasicStats stats)
          Explains the lambda parameter.
 float lambda(BasicStats stats)
          Computes the lambda parameter.
 String toString()
          Subclasses must override this method to return the code of the lambda formula.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

LambdaTTF

public LambdaTTF()
Sole constructor: parameter-free

Method Detail

lambda

public final float lambda(BasicStats stats)
Description copied from class: Lambda
Computes the lambda parameter.

Specified by:
lambda in class Lambda

explain

public final Explanation explain(BasicStats stats)
Description copied from class: Lambda
Explains the lambda parameter.

Specified by:
explain in class Lambda

toString

public String toString()
Description copied from class: Lambda
Subclasses must override this method to return the code of the lambda formula. Since the original paper is not very clear on this matter, and also uses the DFR naming scheme incorrectly, the codes here were chosen arbitrarily.

Specified by:
toString in class Lambda


Copyright © 2000-2013 Apache Software Foundation. All Rights Reserved.