Thanks Matt and Jacob,
There's still something not working yet, but I'm trying to build a MFE
before asking.
Matt, what you say is consistent with plex/tutorials/ex8.c, but not with
DMAdaptorAdapt_Sequence_Private. Does that mean that the latter is broken ?
Thanks
--
Nicolas
On 11/12/2020 18:39, Matthew Knepley wrote:
On Fri, Dec 11, 2020 at 12:02 PM Nicolas Barral
<[email protected]
<mailto:[email protected]>> wrote:
Hi all (and probably more specifically Matt ?)
I am trying to understand how the class IDs of a DM field are set, and
can't find it in the documentation.
A little background, I am mimicking
SNES/utils/dmadapt.c/DMAdaptorAdapt_Sequence_Private for a specific
case
(I'm trying to build the same kind of metric from a single sensor
field,
without all the SNES layer).
I need to compute the gradient of the sensor field, using
DMPlexComputeGradientClementInterpolant, for which I create a DM, to
which I associate a PetscFE, a DS, like in existing code:
PetscFE feGrad
PetscDS probGrad
ierr = PetscFECreateDefault(PetscObjectComm((PetscObject) dmGrad), dim,
coordDim, PETSC_TRUE, NULL, -1, &feGrad);CHKERRQ(ierr);
ierr = PetscDSSetDiscretization(probGrad, f, (PetscObject)
feGrad);CHKERRQ(ierr);
Jacobi is correct, so let me give the history. Originally, you were to
call PetscDSSetDiscretization() as you have done.
However, now it is possible to have different discretization within the
same domain, So now we want you to call
DMAddField(dm, feGrad), and then DMCreateDS(), which will
call PetscDSSetDiscretization() for you. I changed the
examples, but I did not have another place to document this.
Thanks,
Matt
ierr = PetscFEDestroy(&feGrad);CHKERRQ(ierr);
Yet, when I call DMPlexComputeGradientClementInterpolant, I get the
following error:
[0]PETSC ERROR: Unknown discretization type for field 0
I don't fully understand what all these objects are (FE, DS and Field),
and how they are related, where would that be documented ?
And what else do I need to do to make my example work ?
Thanks
--
Nicolas
--
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
https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
