[Users] Carpet version of cctk_bbox?

[Erik Schnetter]

The routine that Roland describes determines what kind of boundary a
boundary is -- inter-processor, symmetry boundary, outer boundary,
etc., but unfortunately does not distinguish between mesh refinement
boundaries and inter-process ghost zones. The reason is that a given
boundary may be both. Consider an L-shaped refined region consisting
of two rectangular component. Where they touch, ghost zones are filled
by copying from the other component, elsewhere, they are filled via
prolongation from the next coarser grid.

Therefore, the distinction between inter-process and mesh refinement
boundaries is hidden from the application, and synchronization applies
both kinds of boundary conditions.

To determine the details, you can query Carpet about which region of a
component are filled by synchronization and which are filled by
prolongation; however, there is no one-to-one connection to what
Cactus calls a "face" of a grid.

Let's discuss on Skype, which should be easier than email.

-erik

On Mon, Apr 9, 2012 at 10:12 AM, Roland Haas
<roland.haas at physics.gatech.edu> wrote:
> Hello  Scott,
>
>>   For my elliptic solver, I need to know not only if a given grid boundary is an outer boundary or not, I need to know if it's an inter-processor boundary or a mesh refinement boundary.
>> cctk_bbox does not provide the latter distinction.  Is there something analogous provided by Carpet?
> GenericFD's GenericFD_GetBoundaryInfo routine (in Kranc, see
> https://github.com/ianhinder/Kranc/blob/6bed8e74aac5bd1e76f2e7a4d8efcf166a60c6e6/Auxiliary/Cactus/KrancNumericalTools/GenericFD/src/GenericFD.c)
> will do this for you. I believe there was discussion at one point to
> move this functionality into the flesh but cannot find the thread right now.
>
> Yours,
> Roland
>
> --
> My email is as private as my paper mail. I therefore support encrypting
> and signing email messages. Get my PGP key from http://keys.gnupg.net.
>
>
> _______________________________________________
> Users mailing list
> Users at einsteintoolkit.org
> http://lists.einsteintoolkit.org/mailman/listinfo/users
>



-- 
Erik Schnetter <schnetter at cct.lsu.edu>
http://www.perimeterinstitute.ca/personal/eschnetter/