RE: Convex Hull
- To: mathgroup at smc.vnet.net
- Subject: [mg20866] RE: [mg20839] Convex Hull
- From: "Ersek, Ted R" <ErsekTR at navair.navy.mil>
- Date: Thu, 18 Nov 1999 01:09:42 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Virgil Stokes wrote: ------------------------------- I have two ellipses that in general are different (lengths of minor/major axes may differ) and are positioned at random in the XY-plane with the condition that they do not overlap or touch at any point along their boundaries. The problem is to find the convex hull for these two ellipses -- fast. Any ideas/suggestions would be appreciated. Please reply direct to my email since I am still unable to get messages generated from the MathGroup list. ------------------- I suppose the ellipses are represented as lists of points inside Line. If not you could use ParametricPlot to make the lists of points. You could then use the convex hull algorithm at: http://www.mathsource.com/Content/Applications/Graphics/2D/0209-854 I don't know if this algorithm can find the convex hull of multiple polygons. If that's a problem you could find a way to connect the polygons into one polygon. I doubt this will run lightning fast, but I don't know how you can do much better. -------------------- Regards, Ted Ersek For Mathematica tips, tricks see http://www.dot.net.au/~elisha/ersek/Tricks.html