Ok, so here’s some behavior I don’t understand. I am working with a
DMComposite structure, and I do the following,
SNESComputeFunction(snes,U_refine,r);
SNESGetDM(snes, &dm_refine);
DMCompositeGetLocalVectors(dm_refine, &rp, &rQ);
DMCompositeScatter(dm_refine, r, rp, rQ);
VecNorm(r, NORM_2, &r_norm);
VecNorm(rp, NORM_2, &rp_norm);
VecNorm(rQ, NORM_2, &rQ_norm);
VecGetSize(r,&r_size);
VecGetSize(rp, &rp_size);
VecGetSize(rQ, &rQ_size);
DMCompositeRestoreLocalVectors(dm_refine, &rp, &rQ);
VecDestroy(&r);
PetscPrintf(PETSC_COMM_WORLD," ||r|| = %g, %i entries\n",r_norm,r_size);
PetscPrintf(PETSC_COMM_WORLD," ||rp|| = %g, %i entries\n",rp_norm,rp_size);
PetscPrintf(PETSC_COMM_WORLD," ||rQ|| = %g, %i entries\n",rQ_norm,rQ_size);
and my output is:
||r|| = 225.31, 7999 entries
||rp|| = 140.021, 3 entries
||rQ|| = 176.56, 8004 entries
The arithmetic, is off, no?
-gideon
> On Sep 10, 2015, at 5:28 PM, Barry Smith <[email protected]> wrote:
>
>
> SNESGetDM() this will return not the original DM you set but the refined
> one.
>
>> On Sep 10, 2015, at 3:47 PM, Gideon Simpson <[email protected]> wrote:
>>
>> I’m using a DMCompsosite along with grid sequencing and here’s what I’m
>> trying to accomplish. After running the SNES solve, I’d like to evaluate
>> the residual on the refined grid, on each piece of the DMComposite. How do
>> I get a DM for the refined grid which I can then use with
>> DMCompositeGetLocalVectors in order to get each piece of the problem? Or is
>> there a better way?
>>
>> -gideon
>>
>
