Class NormalizationZ
java.lang.Object
org.apache.lucene.search.similarities.Normalization
org.apache.lucene.search.similarities.NormalizationZ
Pareto-Zipf Normalization
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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
ConstructorsConstructorDescriptionCallsNormalizationZ(0.3)
NormalizationZ
(float z) Creates NormalizationZ with the supplied parameterz
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Method Summary
Modifier and TypeMethodDescriptionfloat
getZ()
Returns the parameterz
float
tfn
(BasicStats stats, float tf, float len) Returns the normalized term frequency.toString()
Subclasses must override this method to return the code of the normalization formula.Methods inherited from class org.apache.lucene.search.similarities.Normalization
explain
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Constructor Details
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NormalizationZ
public NormalizationZ()CallsNormalizationZ(0.3)
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NormalizationZ
public NormalizationZ(float z) Creates NormalizationZ with the supplied parameterz
.- Parameters:
z
- representsA/(A+1)
whereA
measures the specificity of the language.
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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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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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getZ
public float getZ()Returns the parameterz
- See Also:
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