Hello,<br>this is my third e-mail regarding multi_index containers.<br><br>I&#39;m using them for the process of clustering a huge amount of data (posts from an aple blog from the last 4-5 years)<br>I&#39;m counting Euclidean distance between two clusters, which I store in a multi_index container like the above<br>
<br><i>typedef multi_index_container&lt;<br>    cluster_d,<br>    indexed_by&lt;<br>        ordered_unique&lt;<br>            tag&lt;cluster_pair&gt;,<br>            composite_key&lt;<br>                cluster_d,<br>                BOOST_MULTI_INDEX_MEMBER(cluster_d, int, cluster1),<br>
                BOOST_MULTI_INDEX_MEMBER(cluster_d, int, cluster2)&gt; &gt;,<br>        ordered_non_unique&lt;<br>            tag&lt;cluster_distance&gt;, BOOST_MULTI_INDEX_MEMBER(cluster_d, float, distance)&gt; &gt;<br>&gt; cluster_index;</i><br>
<br><br>My problem is that I have to count 9500! (! = factorial) distances, and store them in the multi_index container.<br>The process of counting distances is costing me 13minutes ( that is because the dimension of each of the two vectors is nearly 1000 or more for which i have to access STL&#39;s maps).<br>
Another 9 minutes takes the insertion using &quot;<code>std::pair&lt;iterator,bool&gt; insert(const value_type&amp; x);</code>&quot;.<br><br>I would like to know if there is another way to do faster insertion.<br>I&#39;ve seen you use mailing list for much complicated problems, and I&#39;m sorry for being a noob.But since i chose to use boost I&#39;d like to stick with that, so I&#39;m kindly asking for your help!<br>
<br>Thank you  in advance<br>Andrew Kokkalis<br><br>