Comments on: Building the Convex Hull http://marknelson.us/2007/08/22/convex/ Programming, mostly. Thu, 09 Sep 2010 10:19:40 +0000 http://wordpress.org/?v=2.2.3 By: MAX http://marknelson.us/2007/08/22/convex/#comment-329024 MAX Wed, 21 Jul 2010 09:37:58 +0000 http://marknelson.us/2007/08/22/convex/#comment-329024 Very useful. Best exposition of an algorithm for finding a convex hull that I've been able to find [2]. Really saved the day ! Thank u ! Very useful. Best exposition of an algorithm for finding a convex hull that I’ve been able to find [2]. Really saved the day ! Thank u !

]]> By: GeoClustering & Boundry Polygons in C# & KML « Programmers Unlimited http://marknelson.us/2007/08/22/convex/#comment-328207 GeoClustering & Boundry Polygons in C# & KML « Programmers Unlimited Tue, 29 Jun 2010 17:06:23 +0000 http://marknelson.us/2007/08/22/convex/#comment-328207 [...] Points[Len] & Points[Len-1] respectively. There is a great animation demonstrating this process here. After the upper and lower partitions are processed (giving us 2 sets of points that we could [...] […] Points[Len] & Points[Len-1] respectively. There is a great animation demonstrating this process here. After the upper and lower partitions are processed (giving us 2 sets of points that we could […]

]]> By: pavan http://marknelson.us/2007/08/22/convex/#comment-321070 pavan Sat, 09 Jan 2010 09:46:31 +0000 http://marknelson.us/2007/08/22/convex/#comment-321070 Very Good explanation Very Good explanation

]]> By: Mark Nelson http://marknelson.us/2007/08/22/convex/#comment-315611 Mark Nelson Thu, 24 Sep 2009 12:00:41 +0000 http://marknelson.us/2007/08/22/convex/#comment-315611 @geoff: I don't know if there is a sublinear solution to this problem, but people love their convex hulls, so it should be easy to find. My solution: be the point, turn in a circle 360 degrees. If all you see is hull all the way around, you're inside. @geoff:

I don’t know if there is a sublinear solution to this problem, but people love their convex hulls, so it should be easy to find.

My solution: be the point, turn in a circle 360 degrees. If all you see is hull all the way around, you’re inside.

]]> By: geoff bolton http://marknelson.us/2007/08/22/convex/#comment-315580 geoff bolton Thu, 24 Sep 2009 05:19:27 +0000 http://marknelson.us/2007/08/22/convex/#comment-315580 Hi! Nice article. You left out one valuable thing in both your description and code: testing whether a point is inside an established hull. Maybe just because it's reasonably trivial =) Perhaps there's a more clever way to do it, but I'd do a O(n) search calling direction() for each line segment on the hull boundary, testing that the point is always on the right-hand side. Hi! Nice article. You left out one valuable thing in both your description and code: testing whether a point is inside an established hull. Maybe just because it’s reasonably trivial =)

Perhaps there’s a more clever way to do it, but I’d do a O(n) search calling direction() for each line segment on the hull boundary, testing that the point is always on the right-hand side.

]]> By: valency http://marknelson.us/2007/08/22/convex/#comment-111654 valency Sat, 05 Apr 2008 16:32:20 +0000 http://marknelson.us/2007/08/22/convex/#comment-111654 Very useful. Best exposition of an algorithm for finding a convex hull that I've been able to find. Very useful. Best exposition of an algorithm for finding a convex hull that I’ve been able to find.

]]> By: guruqu http://marknelson.us/2007/08/22/convex/#comment-37126 guruqu Sat, 29 Sep 2007 15:11:09 +0000 http://marknelson.us/2007/08/22/convex/#comment-37126 Awsome work!! Awsome work!!

]]> By: Federico Feroldi’s blog » Blog Archive » links for 2007-09-26 http://marknelson.us/2007/08/22/convex/#comment-36804 Federico Feroldi’s blog » Blog Archive » links for 2007-09-26 Wed, 26 Sep 2007 20:20:26 +0000 http://marknelson.us/2007/08/22/convex/#comment-36804 [...] » Building the Convex Hull Mark Nelson: Programming, mostly. Finding the Convex Hull of a set of points is an interesting problem in computational geometry. (tags: algorithms c++ graphics math) [...] […] » Building the Convex Hull Mark Nelson: Programming, mostly. Finding the Convex Hull of a set of points is an interesting problem in computational geometry. (tags: algorithms c++ graphics math) […]

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