Modify

Opened 6 years ago

Last modified 5 years ago

#905 new defect

NaNs in ADMBase::gxx using Development Version of ET

Reported by: yosef@… Owned by:
Priority: major Milestone:
Component: Other Version:
Keywords: Cc:

Description

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....

Attachments (2)

Triv.tar.gz (2.2 KB) - added by yosef@… 6 years ago.
Thorn which does an interpolation of one specific point
test.par (14.5 KB) - added by yosef@… 6 years ago.
parfile that showed nans

Download all attachments as: .zip

Change History (5)

Changed 6 years ago by yosef@…

Attachment: Triv.tar.gz added

Thorn which does an interpolation of one specific point

Changed 6 years ago by yosef@…

Attachment: test.par added

parfile that showed nans

comment:1 Changed 6 years ago by Erik Schnetter

It may be that the past timelevels are not correctly initialised. Could you output all timelevels of both the ADMBase and the ML_BSSN variables?

comment:2 Changed 6 years ago by yosef@…

Yes. There are nans in ML_BSSN metric at it=0 in the past two timelevels. They go away if
I replace carpet::init_3_timelevels=yes with carpet::init_fill_levels=yes.

The nans are not in rl=0. They start on rl=1 at the boundary and up to 11 points in for tl=1.
for tl=2, the nans are not on the boundary , but start 12 points in.

comment:3 Changed 5 years ago by Roland Haas

Is this still a concern or was it tracked down to invalid data on the previous timelevels? Is this possibly related to http://lists.einsteintoolkit.org/pipermail/users/2013-May/003009.html ?

Modify Ticket

Change Properties
Set your email in Preferences
Action
as new The ticket will remain with no owner.
Next status will be 'review'.
as The resolution will be set.
to The owner will be changed from (none) to the specified user.
Next status will be 'confirmed'.
The owner will be changed from (none) to anonymous.

Add Comment


E-mail address and name can be saved in the Preferences.

 
Note: See TracTickets for help on using tickets.