org.apache.lucene.search.similarities

Class SimilarityBase.BasicSimScorer

java.lang.Object

org.apache.lucene.search.similarities.Similarity.SimScorer

org.apache.lucene.search.similarities.SimilarityBase.BasicSimScorer

Enclosing class:

SimilarityBase

final class SimilarityBase.BasicSimScorer
extends Similarity.SimScorer

Delegates the score(float, long) and explain(Explanation, long) methods to SimilarityBase.score(BasicStats, double, double) and SimilarityBase.explain(BasicStats, Explanation, double), respectively.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) BasicStats	stats

Constructor Summary

Constructors

Constructor and Description
BasicSimScorer(BasicStats stats)

Method Summary

Modifier and Type	Method and Description
Explanation	explain(Explanation freq, long norm) Explain the score for a single document
(package private) double	getLengthValue(long norm)
float	score(float freq, long norm) Score a single document.

Methods inherited from class java.lang.Object

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

Field Detail

stats

final BasicStats stats

Constructor Detail

BasicSimScorer

BasicSimScorer(BasicStats stats)

Method Detail

getLengthValue

double getLengthValue(long norm)

score

public float score(float freq,
                   long norm)

Description copied from class: Similarity.SimScorer

Score a single document. freq is the document-term sloppy frequency and must be finite and positive. norm is the encoded normalization factor as computed by Similarity.computeNorm(FieldInvertState) at index time, or 1 if norms are disabled. norm is never 0.

Score must not decrease when freq increases, ie. if freq1 > freq2, then score(freq1, norm) >= score(freq2, norm) for any value of norm that may be produced by Similarity.computeNorm(FieldInvertState).

Score must not increase when the unsigned norm increases, ie. if Long.compareUnsigned(norm1, norm2) > 0 then score(freq, norm1) <= score(freq, norm2) for any legal freq.

As a consequence, the maximum score that this scorer can produce is bound by score(Float.MAX_VALUE, 1).

Specified by:

score in class Similarity.SimScorer

Parameters:

freq - sloppy term frequency, must be finite and positive

norm - encoded normalization factor or 1 if norms are disabled

Returns:

document's score

explain

public Explanation explain(Explanation freq,
                           long norm)

Description copied from class: Similarity.SimScorer

Explain the score for a single document

Overrides:

explain in class Similarity.SimScorer

Parameters:

freq - Explanation of how the sloppy term frequency was computed

norm - encoded normalization factor, as returned by Similarity.computeNorm(org.apache.lucene.index.FieldInvertState), or 1 if norms are disabled

Returns:

document's score