[Nek5000-users] Load_fld() without restart

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

Hi Holly,

I'm not quite sure how to estimate how much time is needed to load the .fld
files, it would certainly depend on how many processors you are using,
whether you are using MPI_IO, etc.. (maybe the main developers could give
some sort of leading order complexity here?)

As for the variables, the main variables (vx, vy, vz, pr, t) are
overwritten each time step, although I think there are some lag arrays
available (such as vxlag).  However, I'm not familiar with how these are
used, so you may want to do some digging.

Josh


On Mon, Jan 20, 2014 at 2:51 AM, <nek5000-users at lists.mcs.anl.gov> wrote:

>  Hi Josh,
>
> Thank you for your answer. We had already considered using this approach
> but we have a few queries. We would like to load a .fld file at each time
> step, which means the process might become very costly. Do you have any
> idea of the cost (in time) of such a method? Also, what becomes of the
> variables calculated during the previous time steps?
>
> Thanks again,
>
> Holly
>
> Le 17/01/2014 14:21, nek5000-users at lists.mcs.anl.gov a écrit :
>
> Hi Holly,
>
>  If you wanted to load a .fld file without copying over your variables,
> you could do something like
>
>  ! Create temporary storage
> real tmp1(lx1*ly1*lz1*lelv), tmp2(lx1*ly1*lz1*lelv), ...
>
>  ! Copy simulation fields to temporary variables
> call copy(tmp1,vx,nx1*ny1*nz1*nelv)
> ...
>
>  ! Load field file and do whatever work you want to do with it
>
>  ! Copy simulation fields back to nek variables
> call copy(vx,tmp1,nx1*ny1*nz1*nelv)
>
>
>  You should be able to use some of the Nek scratch arrays to store your
> temporary variables (instead of taking up more memory with the explicit
> declaration), but I'm not sure at the moment which scratch arrays
> load_fld() uses.
>
>  - Josh
>
>
>
> On Fri, Jan 17, 2014 at 4:56 AM, <nek5000-users at lists.mcs.anl.gov> wrote:
>
>> Hi Neks !
>>
>> Is there a way to load a .fld file during a simulation (in the same way
>> load_fld() does) but without doing a complete restart of all the variables ?
>>
>> Thanks for any help !
>>
>> Holly
>> _______________________________________________
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>> Nek5000-users at lists.mcs.anl.gov
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>>
>
>
>
>  --
> Josh Camp
>
> "All that is necessary for the triumph of evil is that good men do
> nothing" -- Edmund Burke
>
>
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-- 
Josh Camp

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