Hi, Lucene 4 has this already: e.g. to enable BM25 ranking use the following Similarity implementation and set it on IndexWriter and IndexSearcher: http://lucene.apache.org/core/4_7_1/core/org/apache/lucene/search/similarities/BM25Similarity.html
The full list is here and documentation is here: http://lucene.apache.org/core/4_7_1/core/org/apache/lucene/search/similarities/package-summary.html#package_description (the links above are to Lucene 4.7.1 documentation). You can also set those in Apache Solr, e.g. here is an example schema: http://searchcode.com/codesearch/view/25293129 The same applies to Elasticsearch: http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/index-modules-similarity.html Uwe ----- Uwe Schindler H.-H.-Meier-Allee 63, D-28213 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de > -----Original Message----- > From: Prakash Dubey [mailto:pkdapa...@gmail.com] > Sent: Thursday, April 03, 2014 1:30 PM > To: java-user@lucene.apache.org > Subject: Ranking Function based on Probabilistic Retrieval Framework > > Dear all, > Why there is no Ranking function based on Probabilistic Retrieval > Framework<http://en.wikipedia.org/wiki/Probabilistic_relevance_model> > (ex.Okapi > BM25) in Lucene. Actually there is third party implementation of the BM25 > Model <http://nlp.uned.es/~jperezi/Lucene-BM25/> but it is no longer > compatible with current release of Lucene. > > *Why we are not planning to start implement in next release.* > > Please see this issue > Thank you, --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
