com.bericotech.clavin.index

Class BinarySimilarity

java.lang.Object

org.apache.lucene.search.similarities.Similarity

org.apache.lucene.search.similarities.TFIDFSimilarity

org.apache.lucene.search.similarities.DefaultSimilarity

com.bericotech.clavin.index.BinarySimilarity

public class BinarySimilarity
extends org.apache.lucene.search.similarities.DefaultSimilarity

Turns TF (term frequency) into a binary (yes/no) proposition in calculating Lucene relevance score.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.similarities.Similarity

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

Field Summary

Fields inherited from class org.apache.lucene.search.similarities.DefaultSimilarity

discountOverlaps

Constructor Summary

Constructors

Constructor and Description
BinarySimilarity() Simple default constructor for BinarySimilarity.

Method Summary

Methods

Modifier and Type	Method and Description
float	tf(float freq) Ignores multiple appearance of the query term in the index document field, effectively making TF (term frequency) a yes/no proposition (i.e., zero is still zero, but you don't get extra points for a query term being found multiple times in an index document field).

Methods inherited from class org.apache.lucene.search.similarities.DefaultSimilarity

coord, decodeNormValue, encodeNormValue, getDiscountOverlaps, idf, lengthNorm, queryNorm, scorePayload, setDiscountOverlaps, sloppyFreq, toString

Methods inherited from class org.apache.lucene.search.similarities.TFIDFSimilarity

computeNorm, computeWeight, idfExplain, idfExplain, simScorer

Methods inherited from class java.lang.Object

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

Constructor Detail

BinarySimilarity

public BinarySimilarity()

Simple default constructor for BinarySimilarity.

Method Detail

tf

public float tf(float freq)

Ignores multiple appearance of the query term in the index document field, effectively making TF (term frequency) a yes/no proposition (i.e., zero is still zero, but you don't get extra points for a query term being found multiple times in an index document field).

Overrides:

tf in class org.apache.lucene.search.similarities.DefaultSimilarity

Parameters:

freq - floating-point number being converted to 1.0 or 0.0