[Users] problem with GenericFD

[Bruno Giacomazzo]

Hi Erik and Ian,
	thanks for the explanation. In the past I never had problems when I was not setting those parameters (particularly the *_upper ones). Anyway I will always make sure to set them in my par files.

Cheers,
Bruno

On Mar 1, 2012, at 2:43 PM, Erik Schnetter wrote:

> On Thu, Mar 1, 2012 at 4:14 PM, Bruno Giacomazzo
> <bruno.giacomazzo at jila.colorado.edu> wrote:
>> Hi Roland,
>> thanks for the prompt reply.
>> 
>> On Mar 1, 2012, at 12:46 PM, Roland Haas wrote:
>> 
>> # Parameters of thorn CoordBase (implementing CoordBase)
>> 
>> CoordBase::boundary_shiftout_x_lower = 1
>> 
>> CoordBase::boundary_shiftout_z_lower = 1
>> 
>> CoordBase::boundary_size_x_lower     = 3
>> 
>> CoordBase::boundary_size_z_lower     = 3
>> 
>> Maybe
>> CoordBase::boundary_size_y_lower     = 3
>> CoordBase::boundary_size_x_upper     = 3
>> CoordBase::boundary_size_y_upper     = 3
>> CoordBase::boundary_size_z_upper     = 3
>> are missing? I certainly use those.
>> 
>> 
>> this fixed the problem.
>> 
>> In the past I never used the *_upper and I used the*_ lower only for those
>> directions where I was applying a symmetry condition. I think the *_upper
>> just extends the grid from xmax to xmax+3*dx, while without them the
>> boundary points are included in xmax. I'm not sure what is the effect of
>> having added also y_lower, but the initial data look correct as before.
> 
> This parameter specifies to other thorns (including Carpet) how many
> boundary zones there are, as explained by Ian.
> 
> If you don't want the grid to become larger in these directions, you
> can set these to "inner" boundaries, which means that the boundary
> zones don't get added to the outside, but rather "relabel" grid points
> that would otherwise be interior grid points. Both are consistent; the
> difference in only where the boundary grid points are located with
> respect to the physical outer boundary. You can also use the shiftout
> parameters to move the boundary points with a similar effect.
> 
> On symmetry boundaries, you need to use "outer" boundaries and a
> "shiftout" of 1 (for vertex centering), as you already do. But you are
> free to specify anything on other boundaries.
> 
> -erik
> 
> -- 
> Erik Schnetter <schnetter at cct.lsu.edu>
> http://www.perimeterinstitute.ca/personal/eschnetter/

Dr. Bruno Giacomazzo
JILA - University of Colorado
440 UCB
Boulder, CO 80309
USA

Tel.  : +1 303-492-0389
Fax  : +1 303-492-5235
email : bruno.giacomazzo at jila.colorado.edu
web: http://www.brunogiacomazzo.org

----------------------------------------------------------------------
There are only 10 types of people in the world:
Those who understand binary, and those who don't
----------------------------------------------------------------------

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.einsteintoolkit.org/pipermail/users/attachments/20120301/987b0ed0/attachment.html