ivory.smrf.model.score

Class BM25ScoringFunction

java.lang.Object

ivory.smrf.model.score.ScoringFunction

ivory.smrf.model.score.BM25ScoringFunction

Direct Known Subclasses:

CascadeBM25ScoringFunction

public class BM25ScoringFunction
extends ScoringFunction

Computes score based on BM25.

Author:

Don Metzler

Constructor Summary

Constructors

Constructor and Description
BM25ScoringFunction()

Method Summary

Methods

Modifier and Type	Method and Description
void	configure(Node domNode) Configures this scoring function.
float	getMaxScore() Returns the maximum possible score.
float	getMinScore() Returns the minimum possible score.
float	getScore(int tf, int docLen) Computes score.
void	initialize(GlobalTermEvidence termEvidence, GlobalEvidence globalEvidence) Initializes this scoring function with global evidence.
void	setB(float b) Sets the b parameter.
void	setK1(float k1) Sets the k1 parameter.
String	toString()

Methods inherited from class ivory.smrf.model.score.ScoringFunction

create, getGlobalEvidence, getGlobalTermEvidence

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

BM25ScoringFunction

public BM25ScoringFunction()

Method Detail

configure

public void configure(Node domNode)

Description copied from class: ScoringFunction

Configures this scoring function.

Overrides:

configure in class ScoringFunction

Parameters:

domNode - DOM node containing configuration data

getMaxScore

public float getMaxScore()

Description copied from class: ScoringFunction

Returns the maximum possible score.

Overrides:

getMaxScore in class ScoringFunction

Returns:

maximum possible score

getMinScore

public float getMinScore()

Description copied from class: ScoringFunction

Returns the minimum possible score.

Overrides:

getMinScore in class ScoringFunction

Returns:

minimum possible score

getScore

public float getScore(int tf,
             int docLen)

Description copied from class: ScoringFunction

Computes score.

Specified by:

getScore in class ScoringFunction

initialize

public void initialize(GlobalTermEvidence termEvidence,
              GlobalEvidence globalEvidence)

Description copied from class: ScoringFunction

Initializes this scoring function with global evidence.

Overrides:

initialize in class ScoringFunction

Parameters:

termEvidence - term evidence

globalEvidence - global evidence

setB

public void setB(float b)

Sets the b parameter.

Parameters:

b - b parameter value

setK1

public void setK1(float k1)

Sets the k1 parameter.

Parameters:

k1 - k1 parameter value

toString

public String toString()

Overrides:

toString in class Object