dolfin team mailing list archive

[Nuno David Lopes <ndl@xxxxxxxxxxxxxx>]

I did forgot something: 
File.cpp changes for xyz format.

Soon I'll add the Cylinder.

On Tuesday 15 July 2008, Anders Logg wrote:
> On Mon, Jul 14, 2008 at 11:44:53PM +0100, ndl@xxxxxxxxxxxxxx wrote:
> > I Hope this works, and that i didn't forget anything.
> > I've followed the manual..clone add commit bundle
>
> Yes, works great.
>
> > By the way about the smooth( ) function,
> > does it works only with convex meshes?
>
> Yes, there are problems for conconvex meshes. I wasn't aware of that,
> but consider a vertex at (0, 0) surrounded by 4 neighboring vertices
> located at
>
>   (0, -epsilon), (0, epsilon), (-1, -C), (1, -C)
>
> and say that the vertex at (0, -epsilon) is fixed (it's a boundary
> vertex).
>
> Then after averaging the neighboring vertices, the new y-coordinate for
> the vertex will be
>
>   (-epsilon + epsilon -C -C) / 4 = -C/2
>
> so by increasing C, we can move the new vertex location arbitrarily
> far below 0 (outside of the domain).
>
> I don't know if there's an easy fix.



-- 
Nuno David Lopes

e-mail:ndl@xxxxxxxxxxxxxx        (FCUL/CMAF)
           nlopes@xxxxxxxxxxxxxxx    (ISEL)
http://ptmat.ptmat.fc.ul.pt/%7Endl/ 

Wed Jul 16 13:55:42 WEST 2008

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