[Carpet] regridding?

[Bela Szilagyi]

How expensive is regridding when called, but with no actual pending 
regrid-requests?

Namely, if I set 

regrid_every > 0

but for most of the simulation I am not asking for any changes in the grid, 
would calles to the CarpetRegrid be much more than a no-op?

Thanks.



On Thursday 04 May 2006 16:30, Bela Szilagyi wrote:
> Can one (or -- is one supposed to) adjust carpet grid structure by steering
> dynamically the parameter CarpetRegrid::coordinates  ?  Obviously, with the
> appropriate
>
>
> CarpetRegrid::refined_regions = manual-coordinate-list
> CarpetRegrid::keep_same_grid_structure = no
>
>
> The reason I am asking is that I tried and have failed.
>
> Originally I had
>
> CartGrid3D::type         = coordbase
> CartGrid3D::avoid_origin = no
>
> CarpetRegrid::refinement_levels = 7
> CarpetRegrid::refined_regions = manual-coordinate-list
> CarpetRegrid::smart_outer_boundaries = yes
> CarpetRegrid::coordinates = "[
>           [ ([0.0,0.0,0.0]:[+20.0,+20.0,+20.0]:[0.4,0.4,0.4]) ],
>           [ ([0.0,0.0,0.0]:[+08.4,+08.4,+09.6]:[0.2,0.2,0.2]) ],
>           [ ([0.0,0.0,0.0]:[+04.2,+04.2,+05.4]:[0.1,0.1,0.1]) ],
>           [ ([0.0,0.0,0.0]:[+02.2,+02.2,+03.4]:[0.05,0.05,0.05]) ],
>           [ ([0.0,0.0,0.0]:[+01.2,+01.2,+02.4]:[0.025,0.025,0.025]) ],
>           [ ([0.0,0.0,0.0]:[+00.6,+00.6,+01.8]:[0.0125,0.0125,0.0125]) ]
> ]"
>
> CarpetRegrid::keep_same_grid_structure = yes
> CarpetRegrid::activate_levels_on_regrid = "function"
> CarpetRegrid::regrid_every = 8
>
>
> Then, after some time I had requested parameter changes as follows:
>
> CarpetRegrid::keep_same_grid_structure = "no"
> CarpetRegrid::coordinates = "[
>              [ ([0.0,0.0,0.0]:[+20.0,+20.0,+20.0]:[0.4,0.4,0.4]) ],
>              [ ([0.0,0.0,0.0]:[+09.0,+09.0,+09.6]:[0.2,0.2,0.2]) ],
>              [ ([0.0,0.0,0.0]:[+04.6,+04.6,+05.4]:[0.1,0.1,0.1]) ],
>              [ ([0.0,0.0,0.0]:[+02.6,+02.6,+03.4]:[0.05,0.05,0.05]) ],
>              [ ([0.0,0.0,0.0]:[+01.6,+01.6,+02.4]:[0.025,0.025,0.025]) ],
>              [ ([0.0,0.0,0.0]:[+00.6,+00.6,+01.8]:[0.0125,0.0125,0.0125]) ]
> ]"
>
> A short time after this parameter change AHFinderDirect quit with the
> complaint
>
> WARNING level -1 in thorn AHFinderDirect processor 2 host ic0141
>   (line 78
> of
> /home/szilagyi/Cactus/configs/harm/build/AHFinderDirect/jtutil/error_exit.c
>c): -> ***** modulo_reduce(): no modulo value is fuzzily within specified
> range! x = 0   xmod = 6.28319
>                        [xmin,xmax] = [0.610865,1.74533]
>                        ==> xx = 0
>
> which suggest incorrect coordinate range.  AHFinderDirect had no problem
> working until the parameter change.  Erik, just to make your argument
> against Jonathan's code more difficult, this is YOUR branch.
>
> Bela.

-- 
Bela Szilagyi
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Max-Planck-Institut für Gravitationsphysik
Albert-Einstein-Institut
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