org.terrier.matching.models.aftereffect

Class LL

java.lang.Object

org.terrier.matching.models.aftereffect.AfterEffect

org.terrier.matching.models.aftereffect.LL

All Implemented Interfaces:

Serializable, Cloneable

public class LL
extends AfterEffect

This class implements the LL model for the first normalisation by after effect. LL stands for the log of laplace succession.

Author:

Ben He

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected String	methodName The name of the model.

Fields inherited from class org.terrier.matching.models.aftereffect.AfterEffect

avl, parameter

Constructor Summary

Constructors

Constructor and Description
LL() The default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
double	gain(double tf, double documentFrequency, double termFrequency) This method computes the gain of encountering an extra token of the query term.
String	getInfo() Returns the name of the method.

Methods inherited from class org.terrier.matching.models.aftereffect.AfterEffect

clone, getParameter, setAverageDocumentLength, setParameter

Methods inherited from class java.lang.Object

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

Field Detail

methodName

protected final String methodName

The name of the model.

See Also:

Constant Field Values

Constructor Detail

LL

public LL()

The default constructor.

Method Detail

getInfo

public String getInfo()

Returns the name of the method.

Specified by:

getInfo in class AfterEffect

Returns:

The name of the method.

gain

public double gain(double tf,
          double documentFrequency,
          double termFrequency)

This method computes the gain of encountering an extra token of the query term.

Specified by:

gain in class AfterEffect

Parameters:

tf - The term frequency in the document

documentFrequency - The document frequency of the term

termFrequency - the term frequency in the collection

Returns:

the gain returned by the implemented formula.