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.

Note

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

Inheritance
System.Object
BasicModel
BasicModelD
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
Namespace: Lucene.Net.Search.Similarities
Assembly: Lucene.Net.dll
Syntax
public class BasicModelD : BasicModel

Constructors

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BasicModelD()

Sole constructor: parameter-free

Declaration
public BasicModelD()

Methods

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Score(BasicStats, Single)

Declaration
public sealed override float Score(BasicStats stats, float tfn)
Parameters
Type Name Description
BasicStats stats
System.Single tfn
Returns
Type Description
System.Single
Overrides
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ToString()

Declaration
public override string ToString()
Returns
Type Description
System.String
Overrides