<div dir="ltr"><div><div><div><div><div><div><div>Thanks, Matt.<br><br></div>And some other questions:<br>1. <a href="http://xapian.org/docs/sourcedoc/html/classXapian_1_1Weight_1_1Internal.html">http://xapian.org/docs/sourcedoc/html/classXapian_1_1Weight_1_1Internal.html</a><br>
</div>    Xapian::doccount collection_size<br></div>                              Number of documents in the collection.<br></div>    What's the difference bewteen collection_size and doccount(Xapian::doccount  get_doccount() const;).<br>
<br></div>2 On this page, <a href="http://xapian.org/docs/bm25.html">http://xapian.org/docs/bm25.html</a><br></div></div><div>    <table border="0"><tbody><tr valign="center"><td><tt><center>
<u>(k₃+1)q</u><br>(k₃+q)</center></tt>
</td>
<td><tt>·</tt></td>
<td>
  <tt><center>
<u>(k₁+1)f</u><br>(k₁L+f)</center></tt>
</td>
<td><tt>·log</tt></td>
<td><tt><center>
<u>(r+0.5)(N-n-R+r+0.5)</u><br>(n-r+0.5)(R-r+0.5)</center></tt>
</td>
<td>
<tt>
 .</tt></td></tr></tbody></table>   f is the wdf, the within document frequency,<br><br></div><div>   But in the code BM25Weight::get_maxpart(), <br>   double wdf_max(get_wdf_upper_bound()) is used, what's the difference between f(wdf) and wdf_max.<br>
</div><div>   If they are not the same, why wdf_max is used<br></div><div>   <br></div><div><div><div><div><div><div><div><table cellpadding="0" cellspacing="0" border="0"><tbody><tr><td class="" align="right" nowrap valign="top">
Really appreciate your help!</td><td class="" valign="bottom"><br></td></tr>

<tr><td class=""><br></td><td class=""><br></td></tr></tbody></table></div></div></div></div></div></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">2013/8/27 Matt Chaput <span dir="ltr"><<a href="mailto:matt@whoosh.ca" target="_blank">matt@whoosh.ca</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5">> Hi, all:<br>
><br>
> I am confused with the concept of colletion_freq<br>
> There's no informations about it on <a href="http://xapian.org/docs/glossary.html" target="_blank">http://xapian.org/docs/glossary.html</a><br>
> What does it means?<br>
<br>
</div></div>The number of times the term appears across all documents.<br>
<br>
<br>
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</blockquote></div><br></div>