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https://issues.apache.org/jira/browse/LUCENE-3440?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13128799#comment-13128799
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Koji Sekiguchi commented on LUCENE-3440:
----------------------------------------

I've removed my latest patch. Because the patch had ASF granted license flag 
but it was not right because it was totally based on sebastian's patch, which 
was not granted to ASF.
                
> FastVectorHighlighter: IDF-weighted terms for ordered fragments 
> ----------------------------------------------------------------
>
>                 Key: LUCENE-3440
>                 URL: https://issues.apache.org/jira/browse/LUCENE-3440
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: modules/highlighter
>    Affects Versions: 3.5, 4.0
>            Reporter: sebastian L.
>            Priority: Minor
>              Labels: FastVectorHighlighter
>             Fix For: 3.5, 4.0
>
>         Attachments: LUCENE-3.5-SNAPSHOT-3440-8.patch, 
> LUCENE-4.0-SNAPSHOT-3440-9.patch, weight-vs-boost_table01.html, 
> weight-vs-boost_table02.html
>
>
> The FastVectorHighlighter uses for every term found in a fragment an equal 
> weight, which causes a higher ranking for fragments with a high number of 
> words or, in the worst case, a high number of very common words than 
> fragments that contains *all* of the terms used in the original query. 
> This patch provides ordered fragments with IDF-weighted terms: 
> total weight = total weight + IDF for unique term per fragment * boost of 
> query; 
> The ranking-formula should be the same, or at least similar, to that one used 
> in org.apache.lucene.search.highlight.QueryTermScorer.
> The patch is simple, but it works for us. 
> Some ideas:
> - A better approach would be moving the whole fragments-scoring into a 
> separate class.
> - Switch scoring via parameter 
> - Exact phrases should be given a even better score, regardless if a 
> phrase-query was executed or not
> - edismax/dismax-parameters pf, ps and pf^boost should be observed and 
> corresponding fragments should be ranked higher 

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