[Nek5000-users] Error in generalev

[nek5000-users at lists.mcs.anl.gov]

Hello Aleks,

I compiled with the option for trapping a floating point exception,
and it gives the message that it trapped the exception in the same
spot as before (which is very odd).

It might be worth mentioning that if I run in post-processing mode
(nsteps=0), it still traps an exception while in userchk (although I
don't think it's anything specific in my userchk, as I've used the
same .usr file before).  The floating point exception occurs when I
make a call to col3 with vx and vx (to get the velocity squared), but
when I calculate the max and min velocities earlier in userchk, I
don't have any issues.

My guess is that something with my geometry is wrong, but it passes
the various geometry checks I see in the logfile.  I'm not sure what
is causing the failure at this point--any thoughts?

Josh

On Wed, Jun 1, 2011 at 6:38 PM,  <nek5000-users at lists.mcs.anl.gov> wrote:
> Hi Josh,
>
> Have you tried to compile with trapping floating point exception?
>
> E.g., the compiler flag for pgf77 is
>
> -Ktrap=fp
>
> Then you may get a better idea where Inf & Nan first appear...
>
> Best,
> Aleks
>
>
>
> On Wed, 1 Jun 2011, nek5000-users at lists.mcs.anl.gov wrote:
>
>> Hello Neks,
>>
>> I've recently come across an error I haven't seen before.    It occurs
>> in the routine "generalev" at the beginning of my run.
>>
>> It looks like the matrix "a" and "b" being fed to the routine have an
>> Infinity or NaN at position (0,0).  Are there any ideas of what could
>> cause this type of error?
>>
>> I have attached the logfile to this email.
>>
>> Thanks,
>>
>> --
>> Josh Camp
>>
>> "All that is necessary for the triumph of evil is that good men do
>> nothing" -- Edmund Burke
>>
> _______________________________________________
> Nek5000-users mailing list
> Nek5000-users at lists.mcs.anl.gov
> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>



-- 
Josh Camp

"All that is necessary for the triumph of evil is that good men do
nothing" -- Edmund Burke