Re: [ff3d-users] Non conforming Mesh & Projection

[Stephane Del Pino]

Le mercredi 14 février 2007 11:28, Cécile Giorla a écrit :
> Hello,
Hello.
> I have two questions :
> 1) How does ff3D reacts when we ask him to solve problem on a non
> conforming mesh?
It should not work: nothing will impose continuity...
But, you can do it using a domain decomposition algorithm (you have to write 
it using the language).

> 2) Is there (or will there be) a function which projects a value
> calculated on a mesh, on another mesh?
Absolutely: you can use L2 projection

------8<--------
solve (u) in m
{
  pde(u)
    u = f;
}
------8<--------

or the weak form:

------8<--------
solve (u) in m
{
  test(v)
    int(u*v) = int(f*v);
}
------8<--------

You can also use H1 projection using the weak formulation:

------8<--------
solve(u) in m
{
  test(v)
    int(u*v)+int(grad(u)*grad(v)) = int(f*v)+int(grad(f)*grad(v));
    u = f on m;
}
------8<--------

Here f is a generic function: it can be analytic or a fem function leaving on 
any mesh ...


Best regards,
Stéphane.