[Users] NaNs between [CCTK_PREREGRID] and [CCTK_PRESTEP]

Erik Schnetter schnetter at cct.lsu.edu
Fri Jun 14 12:59:10 CDT 2019


The major algorithmic step that happens between regridding and
evolution is cycling time levels. At the beginning of each evolution
step, time levels are cycled, so that the current time level of all
evolved variables contain undefined values, to be filled in during
evolution. Since you disabled GRHydro, no time evolution happens, and
these undefined values are detected by the NanChecker.


On Fri, Jun 14, 2019 at 12:57 PM Severin Frank
<severin.frank at uni-tuebingen.de> wrote:
> Dear all,
> My own thorn runs into NaNs just before evolution starts. To search
> where exactly those NaNs are appearing I included subroutines which
> print example values for the corresponding variables and changed the
> schedule position of these output routines. (See SWTNS_inittest and
> SWTNS_regridtest inside the schedule.ccl)
> The last slot inside the schedule where the values still seemed to work,
> is inside [CCTK_PREREGRID]. In [CCTK_PRESTEP] the values are already
> messed up. The only schedule bin that is in between those two is
> [CCTK_POSTREGRID]. I don't have any regridding and whenever I schedule
> my output routine inside the [CCTK_POSTREGRID] bin I don't have any
> output, as you can see in the attached output file.
> Maybe I should point out that I use the Llama Multipatch environment for
> my thorn.
> Does anyone have an idea how I can check what happens with my initial
> data before evolution starts?
> I attached the schedule of my thorn and a simulation output file with
> respect to the (as well attached) parameter file.
> Thanks a lot!
> Best regards,
> Severin
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Erik Schnetter <schnetter at cct.lsu.edu>

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