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Problems with ExtendGraphics/Delaunay Triangulation

  • To: mathgroup at
  • Subject: [mg53567] Problems with ExtendGraphics/Delaunay Triangulation
  • From: jrome at
  • Date: Tue, 18 Jan 2005 05:08:12 -0500 (EST)
  • Sender: owner-wri-mathgroup at


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!

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