Boris,
We will add this support to the DMShell and its usage from PCMG within a
few days.
Barry
> On Mar 11, 2016, at 3:39 PM, Boris Kaus <[email protected]> wrote:
>
>
>> On Mar 11, 2016, at 8:53 PM, Matthew Knepley <[email protected]> wrote:
>>
>> On Fri, Mar 11, 2016 at 12:26 PM, Dave May <[email protected]> wrote:
>> On 11 March 2016 at 18:11, anton <[email protected]> wrote:
>> Hi team,
>>
>> I'm implementing staggered grid in a PETSc-canonical way, trying to build a
>> custom DM object, attach it to SNES, that should later transfered it further
>> to KSP and PC.
>>
>> Yet, the Galerking coarsening for staggered grid is non-symmetric. The
>> question is how possible is it that DMShellSetCreateRestriction can be
>> implemented and included in 3.7 release?
>>
>> It's a little more work than just adding a new method within the DM and a
>> new APIs for DMCreateRestriction() and DMShellSetCreateRestriction().
>> PCMG needs to be modified to call DMCreateRestriction().
>>
>> Dave is correct. Currently, PCMG only calls DMCreateInterpolation(). We
>> would need to add a DMCreateRestriction() call.
> The PCMG object already uses a restriction operator that is different from
> the interpolation parameter if it is specified with PCMGSetRestriction.
> For consistency, one would expect a similar DMCreateRestriction object, not?
> I realize that this is not relevant for FEM codes, but for staggered FD it
> makes quite some difference.
>
> Other suggestions on how to best integrate staggered finite differences
> within the current PETSc framework are ofcourse also highly welcome.
> Our current thinking was to pack it into a DMSHELL (which has the problem of
> not having a restriction interface).
>
> thanks,
> Boris
>
>
>
>
>> Thanks,
>>
>> Matt
>>
>> Please, please.
>>
>> Thanks,
>> Anton
>>
>>
>> --
>> What most experimenters take for granted before they begin their experiments
>> is infinitely more interesting than any results to which their experiments
>> lead.
>> -- Norbert Wiener
>
