lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Zeynep P." <zp...@yahoo.com>
Subject Re: delete entries from posting list Lucene 4.0
Date Tue, 27 Mar 2012 18:25:18 GMT
While using the pruning package, I realised that ridf is calculated in
RIDFTermPruningPolicy as follows:
Math.log(1 - Math.pow(Math.E, termPositions.freq() / maxDoc)) - df 

However, according to the original paper (Blanco et al.) for residual idf,
it should be -log(df/D) + log (1 - e^(*-*tf/D)). Thus, in the equation,
Math.pow should be Math.pow(Math.E, - (termPositions.freq() / maxDoc))

Do I miss something in the calculation or is this a bug? 

Thanks in advance
ZP


--
View this message in context: http://lucene.472066.n3.nabble.com/delete-entries-from-posting-list-Lucene-4-0-tp3838649p3862334.html
Sent from the Lucene - Java Users mailing list archive at Nabble.com.

---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org


Mime
View raw message