hi Erik,
in the LeanBSSNMoL thorn, the lapse gauge condition is implemented (together with all other right-hand-side evaluations) in the file calc_bssn_rhs.F90: https://bitbucket.org/canuda/lean_public/src/master/LeanBSSNMoL/src/calc_bss...
the right-hand-side of the lapse function is done in line 1899:
! rhs_alph rhs_alph = rhs_alph - 2 * alph * trk
so adding another gauge condition should be a matter of changing this line to whatever you want. let me know if this helps!
cheers, Miguel
On 24/10/19 16:43, Erik Rodrígo Jiménez Vázquez wrote:
Thank you!
Of course, any help would be greatly appreciated. What I need to change in the code of the LeanBSSNMoL thorn?
Erik
On Thu, Oct 24, 2019, 10:34 Miguel Zilhão <miguel.zilhao.nogueira@tecnico.ulisboa.pt mailto:miguel.zilhao.nogueira@tecnico.ulisboa.pt> wrote:
hi Erik, you can also try with the LeanBSSNMoL thorn, which is not Kranc-generated. adding another gauge condition should be fairly simple; i can point you exactly to what you'd need to change in the code if you need. cheers, Miguel On 24/10/19 16:21, Peter Diener wrote: > Hi Erik, > > McLachlan is a thorn generated from a tool named Kranc from high level tensorial expressions in > Mathematica. So if you have > access to Mathematica you can add additional lapse conditions in the > mathematica source file located in: > > arrangements/McLachlan/m/McLachlan_BSSN.m > > and then regenerate the McLachlan thorn using > > make McLachlan_BSSN.out > > in the arrangements/McLachlan/m directory. > > I admit the section on gauge conditions is rather messy as the selection of particular gauges are > done based on conditionals on thorn parameters, but hopefully you can figure this out. Otherwise let > me know and I'll be happy to help. > > Cheers, > > Peter > > On Thursday 2019-10-24 00:14, Erik Rodrígo Jiménez Vázquez wrote: > >> Date: Thu, 24 Oct 2019 00:14:05 >> From: Erik Rodrígo Jiménez Vázquez <erjive@ciencias.unam.mx <mailto:erjive@ciencias.unam.mx>> >> To: users@einsteintoolkit.org <mailto:users@einsteintoolkit.org> >> Subject: [Users] Add a lapse condition >> >> Dear all >> >> Is there a way to add different gauge conditions for the lapse? I'm trying >> to add a gauge shock avoid lapse for the Bona-Masso family of slicing >> conditions >> >> dot alpha = -alpha^2 f(alpha) K >> >> with f(alpha)=1+constant/alpha^2 >> >> I don't know if I should add a thorn that complements the McLachlan thorn, >> or what is the correct procedure to implement the gauge condition? >> Furthermore, this kind of gauge condition allows to the lapse become >> negative which I know is a serious drawback when the lapse collapses to >> zero, however I want to do some numerical experiments with this kind of >> lapse. >> >> Any help is very welcome. Thanks >> Erik >> >> >> > > _______________________________________________ > Users mailing list > Users@einsteintoolkit.org <mailto:Users@einsteintoolkit.org> > http://lists.einsteintoolkit.org/mailman/listinfo/users >