<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
Hi,</p><p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial">
<font><font face="Arial, &#39;Helvetica Neue&#39;, Helvetica, sans-serif"><span style="line-height:18px">In continuation of the discussion of melange comments,about negative value returned in matcher due to logarithm of probabilities.</span></font></font></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<i>I</i><i>f we make K suitably large, we could clamp each log(K.Pi) to be &gt;= 0, and this change will only affect really low probability terms (those with Pi &lt; 1/K, so you can adjust K to suit):</i></p><p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<i>W&#39; = sum(i=1,...,n, max(log(K.Pi), 0))</i></p><div><span style="font-size:medium;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif;line-height:18px"><br></span></div><div><span style="font-size:medium;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif;line-height:18px">Did you mean for low probability the the value returned by log(K.Pi) would be negative. So replace lower probability, which still gives negative value by 0?</span></div>
<div><p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><font face="Arial, &#39;Helvetica Neue&#39;, Helvetica, sans-serif" size="3"><span style="line-height:18px">Assigning 0 will be equivalent to rejecting term from the query completely,which hurts the retrieval performance in Language Model as the term missing from the document are smoothened with collection frequency.</span></font></span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><font face="Arial, &#39;Helvetica Neue&#39;, Helvetica, sans-serif" size="3"><span style="line-height:18px">I think we must try the smoothing from collection statistics if the document term probability doesn&#39;t work(is generating negative value).</span></font></span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<em style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">sum(</span></em></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<em style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">i=1,...,n, if( max(log(K.Pi), 0) == 0)</span></em></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<em style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">max(max(log(K.Pcollec.i),0)</span></em></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<em style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">else</span></em></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<em style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"></em><em style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">log(K.Pi)</span></em></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<em style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">)</span></em></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">In case both doesnt work return 0 would be only option .</span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial"><br>
</span></p><p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">Moreover selecting a large enough K would be a tricky task as as no K would be large enough <span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:15px;vertical-align:baseline;background-image:initial;text-decoration:underline">since </span><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:15px;vertical-align:baseline;background-image:initial;text-decoration:underline">log(x) -&gt; -inf as x -&gt; 0</span> </span></span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial">
<span style="font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif;line-height:18px;margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">Should we approach selecting value of K </span><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><font face="Arial, &#39;Helvetica Neue&#39;, Helvetica, sans-serif" size="3"><span style="line-height:18px">by statistically, i will mean to run the unigram Weighting scheme on large collection and observing lowest probability which could be found and hence approximating the value of K </span></font></span><span style="font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif;line-height:18px;font-size:medium">or any other method.</span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial"><br>
</span></p><p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">I asked same Question on Stack overflow about this.</span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<span style="color:rgb(0,83,139);margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial"><a title="Stack overflow Question" href="http://goo.gl/ykwN4" target="_blank" style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial;color:rgb(0,83,139)">http://goo.gl/ykwN4</a></span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<br></p><p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">They suggested:</span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif">
<em style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:medium;vertical-align:baseline;background-image:initial">&quot;</span><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:13px;vertical-align:baseline;background-image:initial;background-color:rgb(250,250,250);color:rgb(68,68,68);font-family:Arial,&#39;Liberation Sans&#39;,&#39;DejaVu Sans&#39;,sans-serif;line-height:17px;text-align:left;background-repeat:initial initial">Could you simple take the negative of the logarithm? Since you are dealing with probabilities (i.e. values &lt;= 1), the logarithm is </span>always<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:13px;vertical-align:baseline;background-image:initial;background-color:rgb(250,250,250);color:rgb(68,68,68);font-family:Arial,&#39;Liberation Sans&#39;,&#39;DejaVu Sans&#39;,sans-serif;line-height:17px;text-align:left;background-repeat:initial initial"> negative, so negating it will </span>always<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:13px;vertical-align:baseline;background-image:initial;background-color:rgb(250,250,250);color:rgb(68,68,68);font-family:Arial,&#39;Liberation Sans&#39;,&#39;DejaVu Sans&#39;,sans-serif;line-height:17px;text-align:left;background-repeat:initial initial"> make it positive.&quot;</span></em></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:12px;vertical-align:baseline;background-image:initial;line-height:18px;font-family:Arial,&#39;Helvetica Neue&#39;,Helvetica,sans-serif;text-align:left">
<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:small;vertical-align:baseline;background-image:initial;color:rgb(68,68,68);font-family:Arial,&#39;Liberation Sans&#39;,&#39;DejaVu Sans&#39;,sans-serif"><span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;font-size:13px;vertical-align:baseline;background-image:initial;line-height:16px">But this approach wont be a good idea as large values will indicates low probabilites,small values will indicate high probabilities.Hence matcher will tend to skip some good documents from ranked list due to lower weight<span style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial;background-color:rgb(250,250,250);line-height:17px">.</span></span></span></p>
<p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial;text-align:left">
<font color="#444444" face="Arial, &#39;Liberation Sans&#39;, &#39;DejaVu Sans&#39;, sans-serif"><span style="line-height:17px"><br></span></font></p><p style="margin-top:0px;margin-right:0px;margin-bottom:8px;margin-left:0px;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;border-style:initial;border-color:initial;outline-width:0px;outline-style:initial;outline-color:initial;vertical-align:baseline;background-image:initial;text-align:left">
<font color="#444444" face="Arial, &#39;Liberation Sans&#39;, &#39;DejaVu Sans&#39;, sans-serif"><span style="line-height:17px">Thanks,</span></font></p></div><b>-- </b><br>with regards<br>Gaurav A.<br>