dolfin team mailing list archive

[Nuno David Lopes <ndl@xxxxxxxxxxxxxx>]

On Thursday 08 May 2008, Anders Logg wrote:
> This really needs to be explained in the manual at some point... :-)
>
> But we (obviously) need a few more iterations on the interface first.
> I agree it's difficult to understand exactly what can be expected when
> assembling over subdomains. The only way to know is to look at the
> code.

My idea is the following:

For now I don't want tu use dS in my  form file and i have a MeshFunction for 
facets with the following markers:
0 for the interior facets

0 for the exterior facets where i will consider zero Neumann boundary    
   conditions, i.e., they have no contribution on assembling

1 for non-zero Neumann boundary condition

2 for other no-zero boundary condition

3 for Dirichlet Boundary condition

It seems that i could use the same MeshFunction in assemble function as in:

assemble(A,a,mesh, cell_domains,facets_domains,facets_domains)

is this right?

If i want to use different markers for the interior facets then i should 
considerer 2 different MeshFunctions   with the correct order. 
0..n-1 for interior 
0..n-1 for exterior
??

And again, if you don't use dS in your forms, the assembler will not take into 
account the third meshfunction, so it could be whatever you want, right?


I'm trying to get into the code, :)

If this works...i hope so
I could try to make a "simple" 
modified demo of the Poisson's demos, or something like that, with different
heat diffusion coefficient's and with different kinds of boundary conditions, 
using this approach, instead of the usual conditional function for 
subdomains.

Thanks...again and again

-- 
Nuno David Lopes