Package org.apache.lucene.search.similarities

Class IndependenceChiSquared

java.lang.Object

org.apache.lucene.search.similarities.Independence

org.apache.lucene.search.similarities.IndependenceChiSquared

public class IndependenceChiSquared
extends Independence

Normalized chi-squared measure of distance from independence

Described as: "can be used for tasks that require high precision, against both short and long queries."

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

Constructor Summary

Constructors

Constructor	Description
IndependenceChiSquared()	Sole constructor.

Method Summary

Modifier and Type	Method	Description
double	score(double freq, double expected)	Computes distance from independence
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

IndependenceChiSquared

public IndependenceChiSquared()

Sole constructor.

Method Details

score

public double score(double freq,
 double expected)

Description copied from class: Independence

Computes distance from independence

Specified by:

score in class Independence

Parameters:

freq - actual term frequency

expected - expected term frequency

toString

public String toString()

Specified by:

toString in class Independence