Hello Ken,
I am following the Parma group's par file to simulate binary neutron stars merging into a black hole. In particular I adopt the following lines into my parfile but it looks like everything is "excised" at the very first iteration (the maximum density suddenly becomes ~10e-11, basically the atmosphere density settings).
Could someone please guide me how this should be done properly? or what parameter settings do I need to set as well?
Sorry for the long delay.
We had a bit of a discussion about this in the last Einstein Toolkit call and you should be able to find some suggestions in the minutes:
http://lists.einsteintoolkit.org/pipermail/users/2021-June/008034.html
Namely:
-8<- ** Black Hole Excision by Hon Ka Hui needs to be answered. They added some lines to the *.par and then excision seemed to occur. Looks like a problem with the Spherical Surface being registered but not set, so it has an infinite radius. They need to set the number of spherical surfaces, perhaps. -8<-
basically it is suggested that you need some parameters for SphericalSurface to be set. See eg the binary black hole star gallery example https://bitbucket.org/einsteintoolkit/einsteinexamples/raw/master/par/GW1509... :
SphericalSurface::nsurfaces = 5 SphericalSurface::maxntheta = 66 SphericalSurface::maxnphi = 124 SphericalSurface::verbose = no
# Surfaces 0 and 1 are used by PunctureTracker
# Horizon 1 SphericalSurface::ntheta [2] = 41 SphericalSurface::nphi [2] = 80 SphericalSurface::nghoststheta [2] = 2 SphericalSurface::nghostsphi [2] = 2
# Horizon 2 SphericalSurface::ntheta [3] = 41 SphericalSurface::nphi [3] = 80 SphericalSurface::nghoststheta [3] = 2 SphericalSurface::nghostsphi [3] = 2
# Common horizon SphericalSurface::ntheta [4] = 41 SphericalSurface::nphi [4] = 80 SphericalSurface::nghoststheta [4] = 2 SphericalSurface::nghostsphi [4] = 2
to make sure that the spherical surface used by AHFinderDirect is actually initialized by making sure nsurfaces is large enough and giving ntheta, nphi etc values for it.
Yours, Roland