Non-overlapping mesh

General Discussion
1

Hi to all,

I created in FF+ a domain which is a square [0,3]x[0,3], using the command “square”, then I add a subdomain [0.9,2.1]x[0.9,2.1] using the “+” operator. Finally a subtracted a subdomain [1.05,1.95]x[1.05,1.95] using the “trunc” command.
I would like to ask please,
how can I generate to this domain with a hole a non-overlapping mesh in FF++?
I’m attaching my code.
If one “zoom” the plot of the mesh the overlapping between the domains can be seen.

Best Regards,
Mordechai.

Backward EG.edp (4.0 KB)

2

You have tons of possibility.

  1. just use trance,
  2. use border with internal border like in https://github.com/FreeFem/FreeFem-sources/blob/master/examples/tutorial/mesh.edp at line 43.
3

Hello professor Hecht,
Thank you for your reply,

  1. Did you mean just use “trunc” command instead of trance?
  2. I would like to use a uniform mesh where the partitions of the domain in x and y directions are equal. If I use the" border" and the “buildmesh” commands, then FF++ will not generate a uniform mesh on the domain.

Best Regards,
Mordechai.

4

Yes I mean trunc

like in

mesh Th=square(20,10,[x*2,y]);
mesh Th1= trunc(Th,x<1.2);
mesh Th2= trunc(Th,x>0.8);
// I do a small movemesh tp seee smoe thing on a plot
plot(Th1,movemesh(Th2,[x+0.01,y]),wait=1,cmm=“Th1”);

5

Thank you very much, Professor Hecht.