[Users] meeting minutes for 2019-09-26

[Zach Etienne]

Hi all,

Regarding this:

> * removed symmetries, 6th order accurate finite differencing,
>   Dissipation to 7th order, increased final time (crash is after
>   t=200M which is normally not reached), found crash in McLachlan
>   (BSSN). Using Dissipation thorn, will send email to mailing list


I just reanalyzed the BaikalETK output for this run. BaikalETK exited due
to NaNs being found at precisely the same iteration as ML_BSSN. *Conclusion:
this doesn't seem to be a ML_BSSN problem at all.* A closer analysis of the
BSSN constraints indicates there's a blow-up near the outer boundary. In
case anyone else wants to take a look, I've attached the parfile. Warning:
requires a few HPC nodes to run.

-Zach

*     *     *
Prof. Zachariah Etienne
Physics & Astronomy Dept.
West Virginia University
http://astro.phys.wvu.edu/zetienne/
http://blackholesathome.net
<https://blackholesathome.net>


On Thu, Sep 26, 2019 at 10:57 AM Haas, Roland <rhaas at illinois.edu> wrote:

> Present: Bill, Helvi, Maria, Peter, Roland, Steve, Yu Liu, Zach
>
> ET release:
> * Fishbone Moncrief:
> - code is not self-contained since NRPy+ is not part of the toolkit
> - NRPy+ itself is BSD license and available
> * self-force code
> - Steve could not checkout and and compile code, was missing effective
>   source code, needs to be organized yet, could be done next week
> - Peter is addressing issues raised in tickets
> https://bitbucket.org/peterdiener/selfforce-1d/issues
> - will go ahead with inclusion
> - code will not be part of the default thornlist, will use its own
>   issue tracker
> - will provide download instructions on ET website, will be mentioned
>   in release announcement
> - Roland suggests to add Cactus-like "Author", "Maintainer" and
>   "License" information to the README file (which are in somewhat
>   machine parseable)
> * release date: move complete freeze to Oct 14th
> * Helvi's group will start running gallery examples
> * Helvi will run test suites on SuperMUC
>
> Tickets relevant to :
> * https://bitbucket.org/einsteintoolkit/tickets/issues/2119/ has made
>   some progress tracking down, have old code so that we can compare,
>   currently do not have a current run with the current evolution code
> * https://bitbucket.org/einsteintoolkit/tickets/issues/2274/ will be
>   reviewed by Steve
>
> BaikalETK:
> * Zach has code done far enough that comparison to McLachlan was
>   possible and waveforms agree for qc0-mclachlan.par
> * removed symmetries, 6th order accurate finite differencing,
>   Dissipation to 7th order, increased final time (crash is after
>   t=200M which is normally not reached), found crash in McLachlan
>   (BSSN). Using Dissipation thorn, will send email to mailing list
>
> Yours,
> Roland
>
> --
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