title: packing algorithm in rtree in boost
body: <p>Hi  all I understand that if rtree is created with range values in boost it would use packing algorithm. I need an example of rtree using packing algorithm. Here is my code that uses quadratic algorithm</p>
  
  <pre><code>    using  point = bg::model::point &lt; int, 2, bg::cs::cartesian &gt;;
      using  pointI = std::pair&lt;point, std::size_t&gt;;
   vector&lt;point&gt; contourCenters // has some value
  bgi::rtree&lt; pointI, bgi::quadratic&lt;16&gt; &gt; rtree;
  vector&lt; pointI &gt; cloud;
  
  for (size_t i = 0; i &lt; contourCenters.size(); ++i)
  {
      int x = contourCenters[i].get &lt; 0 &gt;();
      int y = contourCenters[i].get &lt; 1 &gt;();
  
      cout &lt;&lt; "Contour Centers: (" &lt;&lt; x &lt;&lt; "," &lt;&lt; y &lt;&lt; ")";
      cloud.push_back(mp(x, y, i));
      rtree.insert(make_pair(contourCenters[i], i));
  }
  </code></pre>
  
  <p>I would like to create rtree with packing algorithm as it  seems to be the fastest one in boost. Kindly guide me how to create a rtree with packing algorithm in boost.</p>