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 and Description
IndependenceChiSquared() Sole constructor.

Method Summary

Methods

Modifier and Type	Method and Description
float	score(float freq, float 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 Detail

IndependenceChiSquared

public IndependenceChiSquared()

Sole constructor.

Method Detail

score

public float score(float freq,
          float 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