Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Delaunay triangulation, Maybe a bug
Replies: 1   Last Post: Jun 10, 2014 2:04 AM

 Search Thread: Advanced Search

 Messages: [ Previous | Next ]
 Bruno Luong Posts: 9,822 Registered: 7/26/08
Re: Delaunay triangulation, Maybe a bug
Posted: Jun 10, 2014 2:04 AM
 Plain Text Reply

"h" wrote in message <ln5rso\$ofb\$1@newscl01ah.mathworks.com>...
> Hello everyone,
>
> I use DT = delaunayTriangulation(node) to generate triangles. When I use 15*15 uniform distributed nodes, i get 404 triangular elements. If i am doing the right thing, i think the right answer should be 392 elements.
> I calculated the area of these triangles and I found the area of some triangles are zero.
> Maybe this is a bug. Hope someone can fix it.

I won't consider as BUG, after all delaunay triangulation is a _numerical_ calculation and a regular grid is a singular case for delaunay triangulation: if one of the node move slightly from it's ideal position, the area of the zero-surface becomes > 0.

And I'm not even sure your grid points coordinates can even stored with 100 % accuracy with floating points at the first place.

You just have to deal with this kind of fact in numerical calculation.

Bruno

Date Subject Author
6/9/14 h
6/10/14 Bruno Luong

© The Math Forum at NCTM 1994-2018. All Rights Reserved.