There is doc for tf*idf scoring in the javadoc: http://lucene.apache.org/core/5_0_0/core/org/apache/lucene/search/similarities/TFIDFSimilarity.html
The IndexSearcher#explain method returns an Explanation structure which details the scoring for a document: http://lucene.apache.org/core/5_0_0/core/org/apache/lucene/search/IndexSearcher.html#explain(org.apache.lucene.search.Query, int) -- Jack Krupansky On Fri, Apr 10, 2015 at 4:15 PM, Gregory Dearing <gregdear...@gmail.com> wrote: > Hi Ali, > > The short answer to your question is... there's no good way to create a > score from your result string, without using the Lucene index, that will be > directly comparable to the Lucene score. The reason is that the score > isn't just a function of the query and the contents of the document. It's > also (usually) a function of the contents of the entire corpus... or rather > how common terms are across the entire corpus. > > That being said... the default scoring algorithm is based on tf/idf. The > implementation isn't in any one class... every query type (e.g. Term Query, > Boolean Query, etc...) contains its own code for calculating scores. So > the complete scoring formula will depend on the type of queries you're > using. Many of those implementations also call into the Similarity API > that you mentioned. > > If you'd like to see representative examples of scoring code, then take a > look at TermWeight/TermScorer, and also BooleanWeight, which has several > associated scorers. > > -Greg > > > On Tue, Apr 7, 2015 at 1:32 AM, Ali Akhtar <ali.rac...@gmail.com> wrote: > > > Hello, > > > > I'm in a situation where a search query string is being submitted > > simultaneously to Lucene, and to an external API. > > > > Results are fetched from both sources. I already have a score available > for > > Lucene results, but I don't have a score for the results fetched from the > > external source. > > > > I'd like to calculate scores of results from the API, so that I can rank > > the results by the score, and show the top 5 results from both sources. > > (I.e the results would be merged.) > > > > Is there any Lucene API method, to which I can submit a search string and > > result string, and get a score back? If not, which class contains the > > source code for calculating the score, so that I can implement my own > > scoring class, using the same algorithm? > > > > I've looked at the Similarity class Javadocs, but it doesn't include any > > source code for calculating the score. > > > > Any help would be greatly appreciated. Thanks. > > >
