small space step lead to floating point exception

[Shengyong]

Barry,

Thank you very much!



On Mon, Aug 25, 2008 at 1:19 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
>   You need to determine where the floating point exception occurs. On some
> computers
> this is easy, just run the code in the debugger and use the debugger option
> to trap floating
> point exceptions.  Unfortunately this may not always be possible: in that
> case I would
> start with running with -info -snes_monitor -ksp_monitor to see what is
> happening before
> the floating point exception that is causing the difficulty.
>
>   Barry
>
>
> On Aug 24, 2008, at 7:18 AM, Shengyong wrote:
>
>  Hi,
>>
>> Does anyone happen to meet such convergency problem?  I have implemented a
>> petsc solver
>> to simulate driven cavity flow problem. I use petsc to solve the poisson
>> equation. When I set the space step
>> dx = 1 or 0.01, it works fine. However, when i tried to simulate a meso
>> scale problem, i set dx = 0.0001, dt = 0.00001.
>> I got a error : floating point execption..
>>
>> Does anyone point me out how to solve this problem ?
>>
>>
>>
>>
>>
>> ong
>> Solidification  Simulation Lab,
>> State Key Lab of  Mould & Die Technology,
>> Huazhong Univ. of Sci. & Tech. China
>>
>
>


-- 
Pang Shengyong
Solidification Simulation Lab,
State Key Lab of Mould & Die Technology,
Huazhong Univ. of Sci. & Tech. China
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