Class BasicModelD

Implements the approximation of the binomial model with the divergence for DFR. The formula used in Lucene differs slightly from the one in the original paper: to avoid underflow for small values of N and F, N is increased by 1 and F is always increased by tfn+1.

WARNING: for terms that do not meet the expected random distribution (e.g. stopwords), this model may give poor performance, such as abnormally high scores for low tf values.

This is a Lucene.NET EXPERIMENTAL API, use at your own risk

Inheritance

System.Object

BasicModel

BasicModelD

Inherited Members

BasicModel.Explain(BasicStats, Single)

Namespace: Lucene.Net.Search.Similarities

Assembly: Lucene.Net.dll

Syntax

public class BasicModelD : BasicModel

Constructors

BasicModelD()

Sole constructor: parameter-free

Declaration

public BasicModelD()

Methods

Score(BasicStats, Single)

Declaration

public override sealed float Score(BasicStats stats, float tfn)

Parameters

Type	Name	Description
BasicStats	stats
System.Single	tfn

Returns

Type	Description
System.Single

Overrides

BasicModel.Score(BasicStats, Single)

ToString()

Declaration

public override string ToString()

Returns

Type	Description
System.String

Overrides

BasicModel.ToString()