On Thu, Mar 6, 2014 at 6:28 PM, Furkan KAMACI <furkankam...@gmail.com> wrote: > Hi; > > Tf-Idf is explanation says that: > > *idf(t)* appears for *t* in both the query and the document, hence it is > squared in the equation. > > DefaultSimilarity does not square it. What it the explanation of it?
I think you explained it yourself. The similarity doesn't square it... what is returned from Similarity.idf(t) is used twice (and hence ends up effectively squared). The code has gotten more complex over time, but look at the class IDFStats to see the squaring of idf. There is an idf factor in the queryWeight, and then in normalize() it's multiplied by the idf factor again. -Yonik http://heliosearch.org - native off-heap filters and fieldcache for solr --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
