Package org.apache.lucene.search.similarities

Class Distribution

java.lang.Object

org.apache.lucene.search.similarities.Distribution

Direct Known Subclasses:

DistributionLL, DistributionSPL

public abstract class Distribution
extends Object

The probabilistic distribution used to model term occurrence in information-based models.

See Also:

• IBSimilarity

Constructor Summary

Constructors

Constructor	Description
Distribution()	Sole constructor.

Method Summary

Modifier and Type	Method	Description
Explanation	explain(BasicStats stats, float tfn, float lambda)	Explains the score.
abstract float	score(BasicStats stats, float tfn, float lambda)	Computes the score.
abstract String	toString()	Subclasses must override this method to return the name of the distribution.

Methods inherited from class java.lang.Object

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

Constructor Details

Distribution

public Distribution()

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

Method Details

score

public abstract float score(BasicStats stats,
 float tfn,
 float lambda)

Computes the score.

explain

public Explanation explain(BasicStats stats,
 float tfn,
 float lambda)

Explains the score. Returns the name of the model only, since both tfn and lambda are explained elsewhere.

toString

public abstract String toString()

Subclasses must override this method to return the name of the distribution.

Overrides:

toString in class Object