Uses of Class
org.apache.lucene.search.similarities.SimilarityBase

Packages that use SimilarityBase

Package	Description
org.apache.lucene.search.similarities	This package contains the various ranking models that can be used in Lucene.

Uses of SimilarityBase in org.apache.lucene.search.similarities

Subclasses of SimilarityBase in org.apache.lucene.search.similarities

Modifier and Type	Class	Description
class	Axiomatic	Axiomatic approaches for IR.
class	AxiomaticF1EXP	F1EXP is defined as Sum(tf(term_doc_freq)*ln(docLen)*IDF(term)) where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq
class	AxiomaticF1LOG	F1LOG is defined as Sum(tf(term_doc_freq)*ln(docLen)*IDF(term)) where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq
class	AxiomaticF2EXP	F2EXP is defined as Sum(tfln(term_doc_freq, docLen)*IDF(term)) where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq
class	AxiomaticF2LOG	F2EXP is defined as Sum(tfln(term_doc_freq, docLen)*IDF(term)) where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq
class	AxiomaticF3EXP	F3EXP is defined as Sum(tf(term_doc_freq)*IDF(term)-gamma(docLen, queryLen)) where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq gamma(docLen, queryLen) = (docLen-queryLen)*queryLen*s/avdl NOTE: the gamma function of this similarity creates negative scores
class	AxiomaticF3LOG	F3EXP is defined as Sum(tf(term_doc_freq)*IDF(term)-gamma(docLen, queryLen)) where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq gamma(docLen, queryLen) = (docLen-queryLen)*queryLen*s/avdl NOTE: the gamma function of this similarity creates negative scores
class	DFISimilarity	Implements the Divergence from Independence (DFI) model based on Chi-square statistics (i.e., standardized Chi-squared distance from independence in term frequency tf).
class	DFRSimilarity	Implements the divergence from randomness (DFR) framework introduced in Gianni Amati and Cornelis Joost Van Rijsbergen.
class	IBSimilarity	Provides a framework for the family of information-based models, as described in Stéphane Clinchant and Eric Gaussier.
class	IndriDirichletSimilarity	Bayesian smoothing using Dirichlet priors as implemented in the Indri Search engine (http://www.lemurproject.org/indri.php).
class	LMDirichletSimilarity	Bayesian smoothing using Dirichlet priors.
class	LMJelinekMercerSimilarity	Language model based on the Jelinek-Mercer smoothing method.
class	LMSimilarity	Abstract superclass for language modeling Similarities.