lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Uwe Schindler (JIRA)" <j...@apache.org>
Subject [jira] [Reopened] (LUCENE-3290) add FieldInvertState.numUniqueTerms, Terms.sumDocFreq
Date Sat, 09 Jul 2011 11:17:16 GMT

     [ https://issues.apache.org/jira/browse/LUCENE-3290?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Uwe Schindler reopened LUCENE-3290:
-----------------------------------


I reopen this one:

bq. The FieldInvertState.numUniqueTerms portion is backported to 3.x (no collection level
stats are in 3.x in general, seems tricky)

As we backported this, we must add a Lucene 3.4 backwards index to the TestBackwardsCompatibility
test. And hopefully this new 3.4 Index format opens sucessfully in trunk!

> add FieldInvertState.numUniqueTerms, Terms.sumDocFreq
> -----------------------------------------------------
>
>                 Key: LUCENE-3290
>                 URL: https://issues.apache.org/jira/browse/LUCENE-3290
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: core/index
>            Reporter: Robert Muir
>            Assignee: Robert Muir
>             Fix For: 3.4, 4.0
>
>         Attachments: LUCENE-3290.patch, LUCENE-3290.patch
>
>
> For scoring systems like lnu.ltc (http://trec.nist.gov/pubs/trec16/papers/ibm-haifa.mq.final.pdf),
we need to supply 3 stats:
> * average tf within d
> * # of unique terms within d
> * average number of unique terms across field
> If we add FieldInvertState.numUniqueTerms, you can incorporate the first two into your
norms/docvalues (once we cut over),
> the average tf within d being length / numUniqueTerms.
> to compute the average across the field, we can just write the sum of all terms' docfreqs
into the terms dictionary header,
> and you can then divide this by maxdoc to get the average.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org


Mime
View raw message