[Users] [Einstein Toolkit] #905: NaNs in ADMBase::gxx using Development Version of ET

[Yosef Zlochower]

This was something I stumbled on when trying to test CCE with the
development version of ET. There were nans in the output files for
particular observer radii, and only at early times.



On 05/16/2012 05:09 PM, Einstein Toolkit wrote:
> #905: NaNs in ADMBase::gxx using Development Version of ET
> ---------------------------------+------------------------------------------
>   Reporter:  yosef@…              |        Type:  defect
>     Status:  new                  |    Priority:  major
> Milestone:                       |   Component:  Other
>    Version:                       |    Keywords:
> ---------------------------------+------------------------------------------
>   While testing the CCE in the ET, I stumbled across an issue
>   interpolating the admbase::metric at CCTK_POSTSTEP in GLOBAL mode
>   at particular spatial points.
>
>
>   The "bug" (or parfile/scheduling error) seems to be sensitive to
>   the exact grid setup. Basically, when I use the
>   qc0-mclachlan-CCE_Cauchy.par parfile, I get nans
>   for gxx. I made a small test thorn that only interpolates
>   gxx at a particular point. Nans show up at iteration 1.
>
>   attached is the parfile I used and the test thorn.
>
>
>   Here is the output from the above test thorn:
>   gxx(3.966899,0.000000,-17.630662) =   1.1160523626974641
>    at iter 0 on proc 1
>   gxx(3.966899,0.000000,-17.630662) =   1.1160523626974641
>    at iter 0 on proc 0
>   gxx(3.966899,0.000000,-17.630662) =                 -nan
>    at iter 8 on proc 1
>   gxx(3.966899,0.000000,-17.630662) =                 -nan
>    at iter 8 on proc 0
>   gxx(3.966899,0.000000,-17.630662) =                 -nan
>    at iter 16 on proc 1
>   gxx(3.966899,0.000000,-17.630662) =                 -nan
>    at iter 16 on proc 0
>
>   etc....
>


-- 
Dr. Yosef Zlochower
Center for Computational Relativity and Gravitation
Assistant Professor
School of Mathematical Sciences
Rochester Institute of Technology
85 Lomb Memorial Drive
Rochester, NY 14623

Office:74-2067
Phone: +1 585-475-6103

yosef at astro.rit.edu

CONFIDENTIALITY NOTE: The information transmitted, including
attachments, is intended only for the person(s) or entity to which it
is addressed and may contain confidential and/or privileged material.
Any review, retransmission, dissemination or other use of, or taking
of any action in reliance upon this information by persons or entities
other than the intended recipient is prohibited. If you received this
in error, please contact the sender and destroy any copies of this
information.