I will add DMShellSetGlobalToLocal (and DMShellSetLocalToGlobal).
One other thing: We also need to be do LocalToLocal operations. For the
structured grid case, we call DMDALocalToLocalBegin/End, and for the
unstructured grid case we construct our own VecScatter context
essentially just how it is done in daltol.c for DMDA. Is there a good
reason that there is no DMLocalToLocalBegin/End?
--Richard
On 2/21/13 2:42 PM, Barry Smith wrote:
> On Feb 21, 2013, at 1:39 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
>
>> On Thu, Feb 21, 2013 at 1:31 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>> I don't understand. There is a DMGlobalToLocalBegin/End() which includes
>>
>> } else {
>> ierr = (*dm->ops->globaltolocalbegin)(dm,g,mode == INSERT_ALL_VALUES ?
>> INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES :
>> mode),l);CHKERRQ(ierr);
>> }
>>
>> For Shell, Richard should be able to provide his own begin/end functions.
>> Which in his case he is already calling the VecScatterBegin/End() directly
>> in his code so he should just be able to keep the scatter context he is
>> already creating and use it in shell. No reason to mess with sections or
>> SF, he already has the scatter and just needs to get it into the DMShell and
>> shell should have it as a matter of course. Just because everyone was to
>> lazy to add DMSetGlobalToLocalBegin/End() doesn't mean it should exist. Rich
>> can add it himself trivially and then use (even from Fortran).
>>
>>
>> Yes, if he has VecScatters already that he wants to reuse, this is a fine
>> option. I proposed this interface earlier in this thread.
>>
>> DMShellSetGlobalToLocal(DM dm,PetscErrorCode (*begin)(DM,Vec,InsertMode,
>> Vec),PetscErrorCode (*end)(DM,Vec,InsertMode,Vec));
> Ok, Richard should add this and then end of conversation.
>
> Barry
>
--
Richard Tran Mills, Ph.D.
Computational Earth Scientist | Joint Assistant Professor
Hydrogeochemical Dynamics Team | EECS and Earth & Planetary Sciences
Oak Ridge National Laboratory | University of Tennessee, Knoxville
E-mail: rmills at ornl.gov V: 865-241-3198 http://climate.ornl.gov/~rmills
