[petsc-users] DMCreateMatrix error with Composite (no getlocaltoglobalmapping)

[Mark Adams]

I see there is a DM_Create_Shell that I can out this in.


On Wed, Aug 6, 2014 at 6:31 PM, Mark Adams <mfadams at lbl.gov> wrote:

> Jed, it looks like DM_DA creates its l2gmap in Setup, but DM_Shell does
> not.  This seems to be causing errors when DM_Shell is used in DM_Composit
> and I make a matrix.
>
> I'm thinking I could add this construction to DM_Shell.  DM_Shell does not
> have a Setup method (like DM_DA) but I could create function and set it
> in DMShellCreate, like PetscErrorCode  DMShellCreate(MPI_Comm comm,DM *dm)
> {
>   PetscErrorCode ierr;
>
>   PetscFunctionBegin;
>   PetscValidPointer(dm,2);
>   ierr = DMCreate(comm,dm);CHKERRQ(ierr);
>   ierr = DMSetType(*dm,DMSHELL);CHKERRQ(ierr);
>   ierr = DMSetUp(*dm);CHKERRQ(ierr);
>   dm->ops->getlocaltoglobalmapping = DMGetLocalToGlobalMapping_Shell
>   PetscFunctionReturn(0);
> }
>
> Does this seem like a reasonable approach?
>
>
>
>
>
> On Wed, Aug 6, 2014 at 2:49 PM, Mark Adams <mfadams at lbl.gov> wrote:
>
>> Now that I look at DMShellSetLocalToGlobal, I see that it sets the
>> begin/end functions.  But these are already set.
>>
>> It looks like DMShell's SetType must set something for dm->ops->getlocaltoglobalmapping
>> for DMShell to be usable to get a matrix from a Composite DM.
>>
>>
>> On Wed, Aug 6, 2014 at 2:34 PM, Mark Adams <mfadams at lbl.gov> wrote:
>>
>>> It looks like DMShellCreate does not set dm->ops->getlocaltoglobalmapping,
>>> which is needed for DMCreateMatrix with a composite DM.  I do set a
>>> global and local vector and a matrix.  It looks like I could call DMShellSetLocalToGlobal.
>>>  Should I be doing this?  Seems low level and the kind of thing this using
>>> the DM was supposed to avoid
>>>
>>> This seems like it is simply a copy of a local vector to to local part
>>> of a global vector.
>>>
>>> Mark
>>>
>>>
>>>
>>> On Wed, Aug 6, 2014 at 12:23 PM, Mark Adams <mfadams at lbl.gov> wrote:
>>>
>>>> adding a subject ...
>>>>
>>>>
>>>> On Wed, Aug 6, 2014 at 12:00 PM, Mark Adams <mfadams at lbl.gov> wrote:
>>>>
>>>>> I am moving my code to have the DM create the matrix and am hitting
>>>>> this error in DMGetLocalToGlobalMapping:
>>>>>
>>>>> if (!dm->ops->getlocaltoglobalmapping)
>>>>> SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_SUP,"DM can not create
>>>>> LocalToGlobalMapping");
>>>>>
>>>>> This happens when I create the matrix like this:
>>>>>
>>>>>   call DMCompositeCreate(comm,solver%da,ierr)
>>>>>   call DMSetOptionsPrefix(solver%da,'fsa_',ierr)
>>>>>   call DMCompositeAddDM(solver%da,solver%daphi,ierr)
>>>>>   call DMCompositeAddDM(solver%da,solver%dalam,ierr)
>>>>>   call DMSetFromOptions(solver%da,ierr)
>>>>>   call DMCreateMatrix(solver%da,solver%KKTmat,ierr)
>>>>>
>>>>> I am using DMShell and create them like so:
>>>>>
>>>>>   ! phi DM
>>>>>   call VecCreate(comm,x1Vec,ierr)
>>>>>   call VecSetSizes(x1Vec,N1loc,N1Glob,ierr)
>>>>>    call VecSetFromOptions(x1Vec,ierr)
>>>>>
>>>>>   call DMShellCreate(comm,solver%daphi,ierr)
>>>>>   call DMShellSetGlobalVector(solver%daphi,x1Vec,ierr)
>>>>>   call DMShellSetMatrix(solver%daphi,solver%A0Mat,ierr)
>>>>>   call VecDestroy(x1Vec,ierr)
>>>>>   call DMSetOptionsPrefix(solver%daphi,'phi_',ierr)
>>>>>   call DMSetFromOptions(solver%daphi,ierr)
>>>>>
>>>>>   call VecCreate(PETSC_COMM_SELF,x1Vecloc,ierr)
>>>>>   call VecSetSizes(x1Vecloc,N1loc,N1loc,ierr)
>>>>>   call VecSetFromOptions(x1Vecloc,ierr)
>>>>>   call DMShellSetLocalVector(solver%daphi,x1Vecloc,ierr)
>>>>>   call VecDestroy(x1Vecloc,ierr)
>>>>>
>>>>> All the examples that I see use DMDAs.  I am able to create a global
>>>>> vector with this DM.
>>>>>
>>>>> Any ideas?
>>>>>
>>>>
>>>>
>>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20140806/791ed608/attachment.html>