[Carpet] regridding?

[Christian David Ott]

Hi,

if there is no need for a change of the grid structure 
(no "recomposition/recomposing"), the cpu time consumption is minimal.
It amounts to a few "if" statements.

  - Christian


On Mon, 8 May 2006, Bela Szilagyi wrote:

> 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
> ----------------------------------------------------
> Max-Planck-Institut für Gravitationsphysik
> Albert-Einstein-Institut
> Tel: +49 331 567 7632
> Fax: +49 331 567 7649
> ----------------------------------------------------
>
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>

-------------------------------------------

Christian D. Ott

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