org.apache.lucene.search.similarities

Class BasicModelG

java.lang.Object

org.apache.lucene.search.similarities.BasicModel

org.apache.lucene.search.similarities.BasicModelG

public class BasicModelG
extends BasicModel

Geometric as 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 1 and N is increased by F.

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

Constructor Summary

Constructors

Constructor and Description
BasicModelG() Sole constructor: parameter-free

Method Summary

Modifier and Type	Method and Description
Explanation	explain(BasicStats stats, double tfn, double aeTimes1pTfn) Returns an explanation for the score.
double	score(BasicStats stats, double tfn, double aeTimes1pTfn) Returns the informative content score combined with the after effect, more specifically informationContentScore * aeTimes1pTfn / (1 + tfn).
String	toString() Subclasses must override this method to return the code of the basic model formula.

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicModelG

public BasicModelG()

Sole constructor: parameter-free

Method Detail

score

public final double score(BasicStats stats,
                          double tfn,
                          double aeTimes1pTfn)

Description copied from class: BasicModel

Returns the informative content score combined with the after effect, more specifically informationContentScore * aeTimes1pTfn / (1 + tfn). This function must be non-decreasing with tfn.

Specified by:

score in class BasicModel

explain

public Explanation explain(BasicStats stats,
                           double tfn,
                           double aeTimes1pTfn)

Description copied from class: BasicModel

Returns an explanation for the score. Subclasses must override this method.

Specified by:

explain 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