org.apache.lucene.search.similarities
Class Lambda

java.lang.Object
  org.apache.lucene.search.similarities.Lambda

Direct Known Subclasses:

LambdaDF, LambdaTTF

public abstract class Lambda
extends Object

The lambda (λ_w) parameter in information-based models.

See Also:

IBSimilarity

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

Constructor Summary

Lambda()
Sole constructor.

Method Summary

abstract Explanation	explain(BasicStats stats) Explains the lambda parameter.
abstract float	lambda(BasicStats stats) Computes the lambda parameter.
abstract String	toString() Subclasses must override this method to return the code of the lambda formula.

Methods inherited from class java.lang.Object

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

Constructor Detail

Lambda

public Lambda()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method Detail

lambda

public abstract float lambda(BasicStats stats)

Computes the lambda parameter.

explain

public abstract Explanation explain(BasicStats stats)

Explains the lambda parameter.

toString

public abstract String toString()

Subclasses must override this method to return the code of the lambda formula. Since the original paper is not very clear on this matter, and also uses the DFR naming scheme incorrectly, the codes here were chosen arbitrarily.

Overrides:

toString in class Object