[Users] TwoPunctures data storage

[Erik Schnetter]

Sascha

Yes, a similar method (interpolation instead of evaluation, possibly
after adding more spectral coefficients) was implemented by Marcus
Ansorg in the TwoPunctures thorn as well.

-erik

On Wed, Mar 2, 2016 at 10:42 AM, Sascha Husa <sascha.husa at uib.es> wrote:
> On Wed, Mar 2, 2016 at 4:23 PM, Erik Schnetter <schnetter at cct.lsu.edu> wrote:
>> Alfred
>>
>> Solving the equations is fast, the slow part is evaluating the
>> solution on the finite differencing grid. If you want to use the same
>> grid multiple times you can checkpoint the initial conditions. If you
>> want to use different grids, then you'll have to repeat the slow part
>> anyway.
>
> Hi Erik and all,
>
> some of the time we will just want to run some tests without great
> needs in accuracy.
> Also, for some extreme initial data the spectral solve may already
> take quite long.
>
> We may look into how the spectral solution is evaluated afterwards on
> the finite difference grid, and compare with BAM.
> What we routinely use in BAM is some high order interpolation, which
> we found to be reasonably fast and sufficiently accurate.
>
> cheers,
> -sascha
>
>
>> There are ways to speed this up by sacrificing accuracy. I don't think
>> this makes sense if you want to obtain accurate waveforms, though.
>>
>> -erik
>>
>> On Wed, Mar 2, 2016 at 9:32 AM, Alfred Castro <alfredcastro6 at gmail.com> wrote:
>>> Hi,
>>>
>>> I am a master student at UIB, and starting to use the Einstein Toolkit
>>> for binary black hole evolutions.
>>>
>>> I am using the TwoPunctures thorn for solving the constraints. In
>>> order to speed up tests of grid structures, I would like to just solve
>>> on the spectral grid once, store the data in a file, and reread them
>>> for different evolutions (e.g. with different finite difference
>>> grids). It looks like this is not supported right now. Has anybody
>>> done this already?
>>>
>>> Thanks,
>>>
>>> --
>>> Alfred
>>>
>>> _______________________________________________
>>> 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/
>> _______________________________________________
>> Users mailing list
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-- 
Erik Schnetter <schnetter at cct.lsu.edu>
http://www.perimeterinstitute.ca/personal/eschnetter/