<div dir="auto">Awesome, thanks! </div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Aug 26, 2020, 5:37 PM Roland Haas <<a href="mailto:rhaas@illinois.edu">rhaas@illinois.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello Bilal,<br>
<br>
> When I change, Carpet::max_refinement_levels = 5 (instead of 3). and<br>
> I also changed,<br>
> <br>
> CarpetRegrid2::num_centres = 1<br>
> #CarpetRegrid2::num_levels_1 = 3<br>
> #CarpetRegrid2::radius_1[1] = 1<br>
> #CarpetRegrid2::radius_1[2] = 1<br>
> <br>
> CarpetRegrid2::num_levels_1 = 5<br>
> CarpetRegrid2::radius_1[1] = 5<br>
> CarpetRegrid2::radius_1[2] = 5<br>
> CarpetRegrid2::radius_1[3] = 5<br>
> CarpetRegrid2::radius_1[4] = 5<br>
You are correct in changing both Carpet::max_refinement_levels which<br>
controls the maximum possible number of refinement levels as well as<br>
CarpetRegrid2::num_levels_1 which controls that actual number of<br>
refinement levels used.<br>
<br>
> My simulation runs successfully. but fourth and fifth levels shown<br>
> only nan as follows,<br>
> <br>
> INFO (CT_MultiLevel): === Level 2 ===<br>
> INFO (CT_MultiLevel): * Equation #0: 10 iterations, norm of final residual = 2.5741620337e-05<br>
> INFO (CT_MultiLevel): * Equation #1: 10 iterations, norm of final residual = 8.7340004508e-06<br>
> INFO (CT_MultiLevel): * Equation #2: 10 iterations, norm of final residual = 8.7156879010e-06<br>
> INFO (CT_MultiLevel): * Equation #3: 10 iterations, norm of final residual = 8.6982806224e-06<br>
> INFO (CT_MultiLevel): === Level 3 ===<br>
> INFO (CT_MultiLevel): * Equation #0: 1 iterations, norm of final residual = nan<br>
> INFO (CT_MultiLevel): * Equation #1: 1 iterations, norm of final residual = nan<br>
> INFO (CT_MultiLevel): * Equation #2: 1 iterations, norm of final residual = nan<br>
> INFO (CT_MultiLevel): * Equation #3: 1 iterations, norm of final residual = nan<br>
<br>
> What else should I fix?<br>
<br>
I am not really familiar (at all, never having used it) with<br>
CT_MultiLevel itself. However looking at the parfile<br>
repos/ctthorns/CT_MultiLevel/par/constraints_spherical.par you can see<br>
that it sets:<br>
<br>
CT_MultiLevel::topMGlevel = 2<br>
<br>
and that parameter is described in the thorn's documentation (in the<br>
doc directory or online)<br>
<a href="http://einsteintoolkit.org/thornguide/CTThorns/CT_MultiLevel/documentation.html" rel="noreferrer noreferrer" target="_blank">http://einsteintoolkit.org/thornguide/CTThorns/CT_MultiLevel/documentation.html</a><br>
as:<br>
<br>
--8<--<br>
The only other parameter which must be set to ensure correct operation<br>
is CT_MultiLevel::topMGlevel, which tells the solver which is the finest<br>
refinement level that covers the entire domain in which the equation is<br>
to be solved. All levels below and including this will be used in the<br>
classical multigrid sense (e.g., in a V- or FMG-cycle). The ones above<br>
will be treated as local AMR boxes, and be solved via a multilevel<br>
prescription; presently, this involves simply interpolating the<br>
solution from the topMGlevel refinement level at the end of the<br>
multigrid part and relaxing it progressively, from coarser to finer, on<br>
all the local grids. <br>
--8<--<br>
<br>
so since you changed max_refinement_levels from 3 to 5 I would also<br>
change topMGlevel from 2 to 4.<br>
<br>
Yours,<br>
Roland<br>
<br>
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</blockquote></div>