You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@lucene.apache.org by "David Smiley (JIRA)" <ji...@apache.org> on 2016/03/24 14:22:25 UTC
[jira] [Updated] (LUCENE-6954) More Like This Query: keep fields
separated
[ https://issues.apache.org/jira/browse/LUCENE-6954?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
David Smiley updated LUCENE-6954:
---------------------------------
Issue Type: Bug (was: Improvement)
Summary: More Like This Query: keep fields separated (was: More Like This Query Generation )
(re-titling and classifying as a bug; I think it's a bug)
> More Like This Query: keep fields separated
> -------------------------------------------
>
> Key: LUCENE-6954
> URL: https://issues.apache.org/jira/browse/LUCENE-6954
> Project: Lucene - Core
> Issue Type: Bug
> Components: modules/other
> Affects Versions: 5.4
> Reporter: Alessandro Benedetti
> Labels: morelikethis
> Attachments: LUCENE-6954.patch
>
>
> Currently the query is generated :
> org.apache.lucene.queries.mlt.MoreLikeThis#retrieveTerms(int)
> 1) we extract the terms from the interesting fields, adding them to a map :
> Map<String, Int> termFreqMap = new HashMap<>();
> ( we lose the relation field-> term, we don't know anymore where the term was coming ! )
> org.apache.lucene.queries.mlt.MoreLikeThis#createQueue
> 2) we build the queue that will contain the query terms, at this point we connect again there terms to some field, but :
> ...
> // go through all the fields and find the largest document frequency
> String topField = fieldNames[0];
> int docFreq = 0;
> for (String fieldName : fieldNames) {
> int freq = ir.docFreq(new Term(fieldName, word));
> topField = (freq > docFreq) ? fieldName : topField;
> docFreq = (freq > docFreq) ? freq : docFreq;
> }
> ...
> We identify the topField as the field with the highest document frequency for the term t .
> Then we build the termQuery :
> queue.add(new ScoreTerm(word, topField, score, idf, docFreq, tf));
> In this way we lose a lot of precision.
> Not sure why we do that.
> I would prefer to keep the relation between terms and fields.
> The MLT query can improve a lot the quality.
> If i run the MLT on 2 fields : weSell and weDontSell for example.
> It is likely I want to find documents with similar terms in the weSell and similar terms in the weDontSell, without mixing up the things and loosing the semantic of the terms.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org