<br>Hello Steve,<br><br>I wrote the initial code for the driving_distance, although Anton modified it quite a bit afterwards.<br><br>Basically it uses a slightly modified Dijkstra that traverses the graph from a starting point while measuring the lenght/time along the way. After a set length/time has been reached, *all* the nodes (along with the x,y coordinates) are passed to CGAL to get the outer points and create a concave hull polygon.<br>
<br>The bottleneck here is in the passing of the nodes since in a dense graph, the data can be quite large. Anton and I were trying all sorts of ways to filter first the nodes, but couldn't find an efficient method without loosing accuracy.<br>
<br>Regards,<br><br>Mario.<br><br><br><div class="gmail_quote">On Wed, Mar 7, 2012 at 9:36 AM, Steve Horn <span dir="ltr"><steve@stevehorn.cc></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hello list.
<div><br></div><div>I am interested in digging in more to the driving_distance functions to do some refining and perhaps improve the usefulness of the results (<a href="http://lists.osgeo.org/pipermail/pgrouting-dev/2012-February/000458.html" target="_blank">http://lists.osgeo.org/pipermail/pgrouting-dev/2012-February/000458.html</a>).</div>
<div><br></div><div>Having a hard time deciphering the current implementation, mostly because of my lack of familiarity with c/c++. Is there someone who wouldn't mind giving a synopsis of the overall approach that the algorithm takes?</div>
<div><br></div><div>Thanks!</div>
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