[firedrake] Interpolating data to Function

[Tuomas Karna]

On 07/31/2014 10:40 AM, Lawrence Mitchell wrote:
>
>> On 31 Jul 2014, at 16:40, Tuomas Karna <tuomas.karna at gmail.com> wrote:
>>
>> Lawrence,
>>
>> Another quick question. Is there a mapping somewhere that maps the local nodes stored in func.dat.data to global indices (i.e. nodes of the entire mesh)?
> This does exist, but it won't do what you want, since it's not unique when repartitioning. Essentially it's just an mpi_exscan of the local numbers. The ordering of the local dofs will change on a different number of partitions, so the global ordering will be different too.
>
> In short, the dat.save/dat.load solution works when restarting on the same number of processes, but we don't have a solution at the moment for general restart, but see below.
>
>> I'd like to store the function states to disk so that I could restart simulations. func.dat.save saves the local array for each process. The partitioning however may change between runs, so I'd need to store the global array.
> We don't currently have a mechanism for doing this. Michael Lange has been working on incorporating the  hdf5 io offered by petsc as a replacement for both visualisation output and also check pointing. However, I think it is still work in progress.
>
> Lawrence
OK, good to know. I'll find a workaround for the time being.

- Tuomas