org.apache.lucene.search.similarities
Class BasicModelBE

java.lang.Object
  org.apache.lucene.search.similarities.BasicModel
      org.apache.lucene.search.similarities.BasicModelBE

public class BasicModelBE
extends BasicModel

Limiting form of the Bose-Einstein model. The formula used in Lucene differs slightly from the one in the original paper: F is increased by tfn+1 and N is increased by F

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

NOTE: in some corner cases this model may give poor performance with Normalizations that return large values for tfn such as NormalizationH3. Consider using the geometric approximation (BasicModelG) instead, which provides the same relevance but with less practical problems.

Constructor Summary

BasicModelBE()
Sole constructor: parameter-free

Method Summary

float	score(BasicStats stats, float tfn) Returns the informative content score.
String	toString() Subclasses must override this method to return the code of the basic model formula.

Methods inherited from class org.apache.lucene.search.similarities.BasicModel

explain

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

BasicModelBE

public BasicModelBE()

Sole constructor: parameter-free

Method Detail

score

public final float score(BasicStats stats,
                         float tfn)

Description copied from class: BasicModel

Returns the informative content score.

Specified by:

score in class BasicModel

toString

public String toString()

Description copied from class: BasicModel

Subclasses must override this method to return the code of the basic model formula. Refer to the original paper for the list.

Specified by:

toString in class BasicModel