Re: Problems with ExtendGraphics/Delaunay Triangulation

*To*: mathgroup at smc.vnet.net*Subject*: [mg53701] Re: Problems with ExtendGraphics/Delaunay Triangulation*From*: David Bailey <dave at Remove_Thisdbailey.co.uk>*Date*: Mon, 24 Jan 2005 03:37:22 -0500 (EST)*References*: <csioin$nnr$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

jrome at mail.com wrote: > Hi, > > I've been having a problem with the Delaunay Triangulation command, > "Delaunay" in a Mathematica notebook I am using. The problem is, the > program seems to lock up for certain data sets. Specifically, I have a > 2D array of about 3000 nodes that locks it up. I did some experiments, > and found that it worked fine for the first 1550 nodes, but not the > first 1575 nodes. Upon looking at the data set, I noticed that 4 nodes > in that range (between 1500 & 1575) were consecutively numbered and in > a straight line. When I altered this values by less than 1%, the > Delaunay triangulation worked fine. > > So, I decided to go back to my code (as I was writing this question, as > a matter of fact!), and added a small random number to every value in > my matrix. This is not an ideal solution, but it seems to work for now. > I'd still like to figure out what the problem with the Delaunay > triangulation is, and find out if there are better solutions to my > problem. Thank you very much. You've already been a big help! > I think you should also post a simple example to Wolfram support - after all, the only way they will get rid of bugs like this is iff people tell them about them! David Bailey dbaileyconsultancy.co.uk