lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From John Pailet <9i7svel2zr6u...@jetable.org>
Subject Re: Boost Document
Date Sat, 18 Nov 2006 11:02:30 GMT

Hi Chris,

You are right !!!
Here is the explain output:

----- DOC 222-----home-
40960.0 = fieldWeight(WORD:home in 0), product of:
  1.0 = tf(termFreq(WORD:home)=1)
  1.0 = idf(docFreq=2)
  40960.0 = fieldNorm(field=WORD, doc=0)

----- DOC 111-----home-
40960.0 = fieldWeight(WORD:home in 1), product of:
  1.0 = tf(termFreq(WORD:home)=1)
  1.0 = idf(docFreq=2)
  40960.0 = fieldNorm(field=WORD, doc=1)

As you can see, doc 222 and doc 111 get exactly the same score, even if data
are exactly the same and even id Doc111 boost value is greater than  Doc222
boost value !!!

Is the internal document ID part of score computation ?

How can I solve this problem of gertting same score for different boost
values?

Thanks a lot !

John





Chris Hostetter wrote:
> 
> 
> : When I have 2 documents that have exactly the same data, but different
> boost
> : value.
> : The order does not respect the boost value. It the following exemples,
> the
> : first document of the search is the document with the lower boost
> value...
> : is it a bug ?
> 
> i would suggest you look at the explain output ... but it seems you
> already are: what does that tell you? what scores do the indvidual
> documents get, and how do their explanations differ?
> 
> if i had to guess, i would suspect that your boosts are big enough that
> they become equivilent when byte encoded and stored as fieldNorms (that's
> what happens to document boosts, they get written as part of hte fieldNorm
> for each field in the document) and the only reason you are getting the
> order that you are is because doc2 has a lower internal id then doc1 ....
> if i'm right, then the scores and the explanations would be equal.
> 
> ...does that jive with what you are seeing?
> 
> 
> :
> : Here is my test code:
> :
> : public void testIt() throws IOException, ParseException
> : 	{
> : 		RAMDirectory ramDir = new RAMDirectory();
> : 		IndexWriter writer = new IndexWriter(ramDir, new StandardAnalyzer(),
> : true);
> :
> : 		Document doc1 = new Document();
> : 		Field word = new Field("WORD","home",
> : Field.Store.YES,Field.Index.TOKENIZED);
> : 		word.setBoost(15);
> : 		doc1.add(word);
> : 		Field id = new Field("ID","111", Field.Store.YES,Field.Index.NO);
> : 		doc1.add(id);
> : 		doc1.setBoost(3163);
> :
> : 		Document doc2 = new Document();
> : 		word = new Field("WORD","home",
> Field.Store.YES,Field.Index.TOKENIZED);
> : 		word.setBoost(15);
> : 		doc2.add(word);
> : 		id = new Field("ID","222", Field.Store.YES,Field.Index.NO);
> : 		doc2.add(id);
> : 		doc2.setBoost(3150);
> :
> :
> : 		writer.addDocument(doc2);
> : 		writer.addDocument(doc1);
> :
> : 		writer.optimize();
> : 		writer.close();
> :
> : 		Searcher searcher = new IndexSearcher(ramDir);
> :
> : 		QueryParser queryParserWord = new QueryParser("WORD",new
> : StandardAnalyzer());
> : 		Query query = queryParserWord.parse("home");
> :
> : 		Hits hits = searcher.search(query);
> :
> : 		for (int i = 0; i < hits.length(); i++) {
> : 			System.out.println("----- DOC " + hits.doc(i).get("ID") +"-----" +
> : hits.doc(i).get("WORD")+"-");
> : 			System.out.println(searcher.explain(query,hits.id(i)).toString());
> : 		}
> : 	}
> :
> :
> : Thanks a lot !
> : --
> : View this message in context:
> http://www.nabble.com/Boost-Document-tf2654631.html#a7405959
> : 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
> :
> 
> 
> 
> -Hoss
> 
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> For additional commands, e-mail: java-user-help@lucene.apache.org
> 
> 
> 

-- 
View this message in context: http://www.nabble.com/Boost-Document-tf2654631.html#a7417101
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