<div dir="ltr">x=0 is OK since in a BNS system the BH will form at the origin where the NSs merge (unless there is a kick). These are the parameters I use in my BNS runs:<div><br></div><div>#------------------ahfinderdirect----------------------------------------------<br><br>ahfinderdirect::find_after_individual_time[1]         = 2000 <br>ahfinderdirect::find_after_individual_time[2]         = 2000 <br>ahfinderdirect::find_every                       = 64<br>ahfinderdirect::geometry_interpolator_name         = &quot;Lagrange polynomial interpolation&quot;<br>ahfinderdirect::geometry_interpolator_pars         = &quot;order=4&quot;<br>ahfinderdirect::initial_guess__coord_sphere__radius[1] = 1<br>ahfinderdirect::initial_guess__coord_sphere__radius[2] = 3<br>ahfinderdirect::mask_buffer_thickness    = 0<br>ahfinderdirect::mask_radius_multiplier   = 0.6<br>ahfinderdirect::mask_radius_offset       = 0<br>ahfinderdirect::max_allowable_horizon_radius[1] = 15<br>ahfinderdirect::max_allowable_horizon_radius[2] = 15<br>ahfinderdirect::max_allowable_theta_growth_iterations = 10<br>ahfinderdirect::max_allowable_theta_nonshrink_iterations = 10<br>ahfinderdirect::max_newton_iterations__initial = 50<br>ahfinderdirect::max_newton_iterations__subsequent = 50<br>ahfinderdirect::move_origins             = yes<br>ahfinderdirect::n_horizons               = 2<br><br>ahfinderdirect::origin_x[1]              = 0<br>ahfinderdirect::origin_x[2]              = 0<br>ahfinderdirect::output_h_every           = 64<br>ahfinderdirect::predict_origin_movement  = yes<br>ahfinderdirect::reset_horizon_after_not_finding[1] = no<br>ahfinderdirect::reset_horizon_after_not_finding[2] = no<br>ahfinderdirect::reshape_while_moving     = yes<br><br>ahfinderdirect::surface_interpolator_name = &quot;Lagrange polynomial interpolation&quot;<br>ahfinderdirect::surface_interpolator_pars = &quot;order=4&quot;<br>ahfinderdirect::verbose_level            = &quot;physics details&quot;<br>ahfinderdirect::which_surface_to_store_info[1] = 0<br>ahfinderdirect::which_surface_to_store_info[2] = 1<br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il giorno mar 20 apr 2021 alle ore 19:30 Erik Schnetter &lt;<a href="mailto:schnetter@cct.lsu.edu">schnetter@cct.lsu.edu</a>&gt; ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Maria<br>
<br>
I see that you only set up one horizon. You need to set at least<br>
N_horizons to 2. All parameters that you set for horizon one (those<br>
with array index [1]), will also need to be set for the second<br>
horizons. It&#39;s also weird that the horizon is at x=0; in a binary<br>
system, I&#39;d expect it to be away from the origin.<br>
<br>
You probably want to set<br>
AHFinderDirect::which_surface_to_store_info[2] = 1<br>
to store information about the second horizon in a different spherical surface.<br>
<br>
<br>
-erik<br>
<br>
On Tue, Apr 20, 2021 at 12:56 PM Hamilton, Maria &lt;<a href="mailto:babiuc@marshall.edu" target="_blank">babiuc@marshall.edu</a>&gt; wrote:<br>
&gt;<br>
&gt; Hello,<br>
&gt;<br>
&gt; Could I please get some help in activating the horizon finder correctly in a bns run?<br>
&gt; This is what I have in the par file:<br>
&gt;<br>
&gt; ActiveThorns = &quot;AHFinderDirect&quot;<br>
&gt; AHFinderDirect::find_after_individual_time[1] = 1500<br>
&gt; AHFinderDirect::find_every = 64<br>
&gt; AHFinderDirect::output_h_every = 128<br>
&gt;<br>
&gt; AHFinderDirect::geometry_interpolator_name = &quot;Lagrange polynomial interpolation&quot;<br>
&gt; AHFinderDirect::geometry_interpolator_pars = &quot;order=4&quot;<br>
&gt; AHFinderDirect::surface_interpolator_name = &quot;Lagrange polynomial interpolation&quot;<br>
&gt; AHFinderDirect::surface_interpolator_pars = &quot;order=4&quot;<br>
&gt; AHFinderDirect::which_surface_to_store_info[1] = 0<br>
&gt;<br>
&gt; AHFinderDirect::initial_guess_method [1] = &quot;coordinate sphere&quot;<br>
&gt; AHFinderDirect::initial_guess__coord_sphere__radius[1]   = 0.3<br>
&gt; AHFinderDirect::initial_guess__coord_sphere__x_center[1] = 0.0<br>
&gt;<br>
&gt; AHFinderDirect::N_horizons  = 1<br>
&gt; AHFinderDirect::max_allowable_horizon_radius[1] = 3<br>
&gt; AHFinderDirect::reset_horizon_after_not_finding[1] = &quot;no&quot;<br>
&gt;<br>
&gt; AHFinderDirect::origin_x[1] = 0<br>
&gt; AHFinderDirect::move_origins = &quot;yes&quot;<br>
&gt; AHFinderDirect::predict_origin_movement = &quot;yes&quot;<br>
&gt; AHFinderDirect::reshape_while_moving = &quot;yes&quot;<br>
&gt;<br>
&gt; AHFinderDirect::track_origin_from_grid_scalar[1] = &quot;yes&quot;<br>
&gt; AHFinderDirect::track_origin_source_x[1] = &quot;Hydro_Analysis::Hydro_Analysis_rho_max_loc[0]&quot;<br>
&gt; AHFinderDirect::track_origin_source_y[1] = &quot;Hydro_Analysis::Hydro_Analysis_rho_max_loc[1]&quot;<br>
&gt; AHFinderDirect::track_origin_source_z[1] = &quot;Hydro_Analysis::Hydro_Analysis_rho_max_loc[2]&quot;<br>
&gt; AHFinderDirect::track_origin_from_grid_scalar[2] = &quot;yes&quot;<br>
&gt; AHFinderDirect::track_origin_source_x[2] = &quot;Hydro_Analysis::Hydro_Analysis_rho_max_loc[0]&quot;<br>
&gt; AHFinderDirect::track_origin_source_y[2] = &quot;Hydro_Analysis::Hydro_Analysis_rho_max_loc[1]&quot;<br>
&gt; AHFinderDirect::track_origin_source_z[2] = &quot;Hydro_Analysis::Hydro_Analysis_rho_max_loc[2]&quot;<br>
&gt;<br>
&gt;<br>
&gt; And this is what happens when is activated:<br>
&gt;<br>
&gt; cactus_bns: /home/babiuc/ET_2020_11/Cactus/configs/bns/build/AHFinderDirect/driver/Newton.cc:109: void AHFinderDirect::track_origin(const cGH*, AHFinderDirect::patch_system&amp;, AHFinderDirect::AH_data*, int, bool): Assertion `ox&#39; failed.<br>
&gt; Rank 0 with PID 22304 received signal 6<br>
&gt; Writing backtrace to BNS_BSSN_Sly_myAHF_dx12/backtrace.0.txt<br>
&gt; -------------------------------------------------------<br>
&gt; Primary job  terminated normally, but 1 process returned<br>
&gt; a non-zero exit code. Per user-direction, the job has been aborted.<br>
&gt;<br>
&gt;<br>
&gt; thanks,<br>
&gt; Maria<br>
&gt; _______________________<br>
&gt; Maria C. Babiuc Hamilton, Ph.D.<br>
&gt; Professor, Department of Physics<br>
&gt; College of Science, Marshall University,<br>
&gt; 1 John Marshall Drive, Huntington, WV, 25755<br>
&gt; Room S 257, Phone: (304)696-2754<br>
&gt;<br>
&gt; _______________________________________________<br>
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<br>
<br>
<br>
-- <br>
Erik Schnetter &lt;<a href="mailto:schnetter@cct.lsu.edu" target="_blank">schnetter@cct.lsu.edu</a>&gt;<br>
<a href="http://www.perimeterinstitute.ca/personal/eschnetter/" rel="noreferrer" target="_blank">http://www.perimeterinstitute.ca/personal/eschnetter/</a><br>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><p><font color="#000000">Pr<font face="arial, sans-serif">of. Bruno Giacomazzo<br>Department of Physics<br>University of Milano-Bicocca<br></font></font><span style="color:rgb(0,0,0)"><font face="arial, sans-serif">Piazza della Scienza 3<br></font></span><span style="color:rgb(0,0,0)"><font face="arial, sans-serif">20126 Milano<br></font></span><span style="font-size:12.8px;color:rgb(0,0,0)">Italy</span></p><p><font color="#000000"><span style="font-size:12.8px">email: </span><span style="font-size:12.8px"><a href="mailto:bruno.giacomazzo@unimib.it" target="_blank">bruno.giacomazzo@unimib.it</a><br></span><span style="font-size:12.8px">phone: (+39) 02 6448 2321</span></font><br><font color="#000000"><span style="font-size:12.8px">web: </span></font><span style="color:rgb(0,0,0);font-size:12.8px"><a href="http://www.brunogiacomazzo.org/" style="font-size:12.8px" target="_blank">http://www.brunogiacomazzo.org</a></span></p><p><font color="#000000">----------------------------------------------------------------------<br><span style="font-size:12.8px">There are only 10 types of people in the world:<br></span><span style="font-size:12.8px">Those who understand binary, and those who don&#39;t<br></span><span style="font-size:12.8px">----------------------------------------------------------------------<br></span></font></p></div></div></div></div></div></div></div>