Class Normalization

This class acts as the base class for the implementations of the term frequency normalization methods in the DFR framework.

This is a Lucene.NET EXPERIMENTAL API, use at your own risk
Inheritance
System.Object
Normalization
Normalization.NoNormalization
NormalizationH1
NormalizationH2
NormalizationH3
NormalizationZ
Namespace: Lucene.Net.Search.Similarities
Assembly: Lucene.Net.dll
Syntax
public abstract class Normalization : object

Constructors

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Normalization()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Declaration
public Normalization()

Methods

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Explain(BasicStats, Single, Single)

Returns an explanation for the normalized term frequency.

The default normalization methods use the field length of the document and the average field length to compute the normalized term frequency. This method provides a generic explanation for such methods. Subclasses that use other statistics must override this method.

Declaration
public virtual Explanation Explain(BasicStats stats, float tf, float len)
Parameters
Type Name Description
BasicStats stats
System.Single tf
System.Single len
Returns
Type Description
Explanation
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Tfn(BasicStats, Single, Single)

Returns the normalized term frequency.

Declaration
public abstract float Tfn(BasicStats stats, float tf, float len)
Parameters
Type Name Description
BasicStats stats
System.Single tf
System.Single len

the field length.

Returns
Type Description
System.Single
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ToString()

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

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

See Also