org.apache.nutch.indexer
Class NutchSimilarity

java.lang.Object
  org.apache.lucene.search.Similarity
      org.apache.lucene.search.DefaultSimilarity
          org.apache.nutch.indexer.NutchSimilarity

All Implemented Interfaces:

Serializable

public class NutchSimilarity
extends DefaultSimilarity

Similarity implementatation used by Nutch indexing and search.

See Also:

Serialized Form

Field Summary

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

discountOverlaps

Fields inherited from class org.apache.lucene.search.Similarity

NO_DOC_ID_PROVIDED

Constructor Summary

NutchSimilarity()

Method Summary

float	coord(int overlap, int maxOverlap)
float	lengthNorm(String fieldName, int numTokens) Normalize field by length.

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

computeNorm, getDiscountOverlaps, idf, queryNorm, setDiscountOverlaps, sloppyFreq, tf

Methods inherited from class org.apache.lucene.search.Similarity

decodeNorm, encodeNorm, getDefault, getNormDecoder, idfExplain, idfExplain, scorePayload, setDefault, tf

Methods inherited from class java.lang.Object

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

Constructor Detail

NutchSimilarity

public NutchSimilarity()

Method Detail

lengthNorm

public float lengthNorm(String fieldName,
                        int numTokens)

Normalize field by length. Called at index time.

Overrides:

lengthNorm in class DefaultSimilarity

coord

public float coord(int overlap,
                   int maxOverlap)

Overrides:

coord in class DefaultSimilarity