[Users] Fwd: SphericalSurfaces + QuasiLocalMeasures + AHFinderDirect

[Leonardo Werneck]

He Erik,

Thanks for the response!

The puncture is placed at x=5 because of the nature of the grid used by the
elliptic solver. However, when the solution is interpolated to the carpet
grid the position of the puncture is shifted to x=0 (this is controlled by
the parameter NRPyEllipticET::position_shift[0]; please see the attached
plot of the lapse function at t=0).

Cheers,
Leo

[image: image.png]



On Wed, Jun 28, 2023 at 1:49 PM Erik Schnetter <schnetter at gmail.com> wrote:

> Leonardo
>
> I've briefly looked at the parameter file. The horizon finder needs to
> know an initial guess for both position and shape of the horizon. You
> are setting this location to 0, but are placing the puncture at x=5.
> The horizon finder then fails. QuasiLocalMeasures then sees that there
> is no horizon and does not run.
>
> -erik
>
> On Wed, Jun 28, 2023 at 3:50 PM Leonardo Werneck <wernecklr at gmail.com>
> wrote:
> >
> > Dear all,
> >
> > I am trying to create a simple parfile to help a PhD student. The goal
> is to set up puncture initial data with NRPyEllipticET and then use
> QuasiLocalMeasures/AHFinderDirect to compute properties of the punctures
> and compare with the expected results. No evolution thorn is
> expected/required and the simulation ends after the initial data has been
> set and the first round of analysis has finished.
> >
> > The parfile attached partially works. The puncture initial data is set
> up and NRPyEllipticET's output is what I'd expect. However, the diagnostics
> are clearly wrong since: 1) AHFinderDirect fails to find the puncture (in
> this example I am setting the mass of one of the punctures to zero); and 2)
> the QuasiLocalMeasures diagnostics is never triggered, despite being
> scheduled.
> >
> > Could someone provide some guidance on how to set up these thorns
> correctly, specifically SphericalSurfaces, QuasiLocalMeasures, and
> AHFinderDirect? Am I missing additional thorns?
> >
> > Also, if someone has a working TwoPuncture example parfile instead,
> please share it with me as I'd be happy to adapt it!
> >
> > Thanks in advance!
> > Leo
> >
> > --
> > ------------------------------
> > Dr. Leonardo R. Werneck, Ph.D.
> > _______________________________________________
> > Users mailing list
> > Users at einsteintoolkit.org
> > http://lists.einsteintoolkit.org/mailman/listinfo/users
>
>
>
> --
> Erik Schnetter <schnetter at gmail.com>
> http://www.perimeterinstitute.ca/personal/eschnetter/
>
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