Class NormalizationH1
java.lang.Object
org.apache.lucene.search.similarities.Normalization
org.apache.lucene.search.similarities.NormalizationH1
Normalization model that assumes a uniform distribution of the term frequency.
While this model is parameterless in the original article, information-based models (see IBSimilarity
) introduced a multiplying factor. The default value for the c
parameter is
1
.
- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.search.similarities.Normalization
Normalization.NoNormalization
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Constructor Summary
ConstructorDescriptionCallsNormalizationH1(1)
NormalizationH1
(float c) Creates NormalizationH1 with the supplied parameterc
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Method Summary
Modifier and TypeMethodDescriptionexplain
(BasicStats stats, double tf, double len) Returns an explanation for the normalized term frequency.float
getC()
Returns thec
parameter.final double
tfn
(BasicStats stats, double tf, double len) Returns the normalized term frequency.toString()
Subclasses must override this method to return the code of the normalization formula.
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Constructor Details
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NormalizationH1
public NormalizationH1(float c) Creates NormalizationH1 with the supplied parameterc
.- Parameters:
c
- hyper-parameter that controls the term frequency normalization with respect to the document length.
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NormalizationH1
public NormalizationH1()CallsNormalizationH1(1)
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Method Details
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tfn
Description copied from class:Normalization
Returns the normalized term frequency.- Specified by:
tfn
in classNormalization
len
- the field length.
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explain
Description copied from class:Normalization
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.
- Overrides:
explain
in classNormalization
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toString
Description copied from class:Normalization
Subclasses must override this method to return the code of the normalization formula. Refer to the original paper for the list.- Specified by:
toString
in classNormalization
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getC
public float getC()Returns thec
parameter.- See Also:
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