<div dir="ltr">Hello Roland,<div>thank you for the explanation. </div><div>Actually, I did mean the fifth reflevel (e.g. level "4", counting from 0). My thoughts were the following: if the finest reflevel is the eighth (that is reflevel "7"), at this reflevel the code is executed at each iteration; on reflevel "6", every two iterations; on reflevel "5", every four iterations and on reflevel "4" (on which I get the crash) every eight iterations. So everything should be correct, if I have understood you answer.</div><div>Thanks again!</div><div>Cheers,</div><div>Giulia</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il giorno gio 14 nov 2019 alle ore 18:22 Haas, Roland <<a href="mailto:rhaas@illinois.edu">rhaas@illinois.edu</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">Hello Giulia,<br>
<br>
this has to do with the order of timesteps when doing subcycling in<br>
time (which is what Carpet does).<br>
<br>
cctk_iteration counts RHS evaluations, and is not directly related to<br>
cctk_time ie cctk_time != cctk_iteration * DELTA_TIME.<br>
<br>
Basically the coarsest reflevel has to step first, so that in iteration<br>
1 (evaluating the RHS for the first time) all reflevels 0..7 step<br>
forward and evaluate the RHS in the EVOL bin.<br>
<br>
In the ANALYSIS bin code only runs once data has been properly<br>
restricted from the finer ones etc. Which happens at slightly different<br>
times than EVOL.<br>
<br>
The net result is that in *EVOL* a function runs in refinement levels<br>
whenever (cctk_iteration - 1) % reflevel_every == 0 while in *ANALYSIS*<br>
it is cctk_iteration % reflevel_every == 0. The strange rule in EVOL<br>
comes from asking "was the last iteration one where the timelevel was<br>
aligned so that I now need to compute a new RHS"?<br>
<br>
Thus 473 - 1 = 472 which is evenly divided by 8. NB you say reflevel 4,<br>
but do you mean the fourth reflevel (which is level "3" since they<br>
count from "0")?<br>
<br>
Yours,<br>
Roland<br>
<br>
> Hi all,<br>
> I am using GRHydro in running a simulation, and I get a crash in<br>
> Con2Prim at iteration 473 on reflevel 4. Given that I have set 8<br>
> refinement levels, I'm wondering why Con2Prim is being executed at<br>
> iteration 473 on this reflevel: shouldn't it be executed only at an<br>
> iteration which is a multiple of 8? Maybe I'm missing something<br>
> fundamental. Thank you,<br>
> Cheers,<br>
> Giulia Crotti<br>
<br>
<br>
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</blockquote></div>