[Users] Cartoon2D and Carpet

[Luca Baiotti]

Hi Erik,

thanks for adding the example parameter file.

Luca



On 5/29/15 12:45 AM, Erik Schnetter wrote:
> Luca
> 
> This check ensures that there is one active grid point in the y
> direction, and that the number of symmetry (i.e. boundary) points is the
> same as the number of ghost points.
> 
> This needs to hold independent of Carpet. If CarpetRegrid2 chooses a
> different domain size, then this is wrong, and you will need to correct
> the parameter file.
> 
> I have just added a test file to Cartoon2D. Look in particular at the
> CoordBase parameters there.
> 
> -erik
> 
> 
> On Thu, May 28, 2015 at 3:26 AM, Luca Baiotti
> <baiotti at ipc.phys.sci.osaka-u.ac.jp
> <mailto:baiotti at ipc.phys.sci.osaka-u.ac.jp>> wrote:
> 
>     Hello,
> 
>     I have a question about CactusNumerical/Cartoon2D.
> 
>     In the source file ApplyCartoon.c, there is a condition for the grid
>     setup:
> 
>     if(cctk_gsh[1] != 2*cctk_nghostzones[1]+1)
>         {
>                 CCTK_WARN(0, "Grid size in y direction inappropriate.");
>          }
> 
>     As far as I could tell, this is generally violated in multilevel
>     Carpet (CarpetRegrid2) runs, with standard settings that determine the
>     minimum extension of the refined grids, like
>     Carpet::use_buffer_zones = yes
>     mol::ode_method          = rk4
> 
>     That condition for Cartoon2D can be achieved on the coarsest level by
>     setting CoordBase::ymax equal to the spacing dy and CoordBase::ymin
>     equal to -dy. But it cannot be set for refined levels, because
>     CarpetRegrid2 adds as many points as required for the buffer zones.
>     Indeed, Carpet adds enough buffer points for its own purposes that
>     Cartoon2D seems to work fine.
> 
>     Should the above condition be changed to
> 
>     if(cctk_gsh[1] >= 2*cctk_nghostzones[1]+1)
> 
>     ?
> 
>     Yours,
>     Luca
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> 
> 
> 
> -- 
> Erik Schnetter <schnetter at cct.lsu.edu <mailto:schnetter at cct.lsu.edu>>
> http://www.perimeterinstitute.ca/personal/eschnetter/