hy,
i have troubles in find the correspondance betwwen the javadoc and faq
similarity expression

in the Similarity Javadoc

score(q,d) =Sum [tf(t in d) * idf(t) * getBoost(t.field in d) *
lengthNorm(t.field in d)  * coord(q,d) * queryNorm(q) ]

in the FAQ

score_d = sum_t(tf_q * idf_t / norm_q * tf_d * idf_t / norm_d_t * boost_t) *
coord_q_d

In FAQ | In Javadoc
1 / norm_q = queryNorm(q)
1 / norm_d_t=lengthNorm(t.field in d)
coord_q_d=coord(q,d)
boost_t=getBoost(t.field in d)
idf_t=idf(t)
tf_d=tf(t in d)

but
where is the javadoc expression for "tf_q" faq expression

nicolas

----- Original Message ----- 
From: "Nicolas Maisonneuve" <[EMAIL PROTECTED]>
To: "Lucene Users List" <[EMAIL PROTECTED]>
Sent: Sunday, January 18, 2004 9:33 PM
Subject: Re: theorical informations


> thanks Karl !
>
> ----- Original Message ----- 
> From: "Karl Koch" <[EMAIL PROTECTED]>
> To: "Lucene Users List" <[EMAIL PROTECTED]>
> Sent: Sunday, January 18, 2004 9:22 PM
> Subject: Re: theorical informations
>
>
> > Actually, finding an answer to this question is not really important.
More
> > important is if you can do what you want with it. If you result comes
from
> a
> > prob. model or a vector space model, who cares if you just want to give
a
> > query and back a hit list of results?
> >
> > Possibliy some people here will strongly disagree... ;-) (?)
> >
> > Karl
> >
> > > Hello Nicolas,
> > >
> > > I am sure you mean IR (Information Retrieval) Model. Lucene implements
a
> > > Vector Space Model with integrated Boolean Model. This means the
Boolean
> > > model
> > > is integrated with a Boolean query language but mapped into the Vector
> > > Space.
> > > Therefore you have ranking even though the traditional Boolean model
> does
> > > not
> > > support this. Cosine similarity is used to measure similarity between
> > > documents and the query. You can find this in a very long dicussion
here
> > > when you
> > > search the archive...
> > >
> > > Karl
> > >
> > > > hy ,
> > > > i have 2  theorycal questions :
> > > >
> > > > i searched in the mailing list the R.I. model implemented in Lucene
,
> > > > but no precise answer.
> > > >
> > > > 1) What is the R.I model implemented in Lucene ? (ex: Boolean Model,
> > > > Vector Model,Probabilist Model, etc... )
> > > >
> > > > 2) What is the theory Similarity function  implemented in Lucene
> > > > (Euclidian, Cosine, Jaccard, Dice)
> > > >
> > > > (why this important informations is not in the Lucene Web site or in
> the
> > >
> > > > faq ? )
> > > >
> > >
> > > -- 
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>
>
>
>
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