Barry,
So adding the call to MatSetBlockSize to the preallocator does fix the error,
but that is not necessary if I simply replace the call to
MatPreallocaterPreallocate with a call to MatMPIAIJSetPreallocation.
And it’s confusing to me especially in light of this exchange a couple months
ago
Because you create the DMDA with a dof of 3, this triggers any matrices it
creates and the localtoglobalmapping object it creates to have a block size of
three. The error you are seeing is that a localtoglobal with a block size of 3
cannot be attached to a matrix with a block size of 1.
T
Why do I have to set the block size to 3? I’m not trying to create a block
matrix.
In fact just a couple months ago I was told I don’t have block matrices and I
had to remove calls to set the block size:
https://lists.mcs.anl.gov/mailman/htdig/petsc-users/2022-May/046094.html
This works fine w
I'm hoping that it is as simple as that you did not set the block size of
your newly created matrix to 3?
> On Jul 29, 2022, at 4:04 PM, Randall Mackie wrote:
>
> Hi Barry,
>
> It seems like this should be trivial to get working but so far I’ve been
> unsuccessful.
> Most likely I’m doin
Hi Barry,It seems like this should be trivial to get working but so far I’ve been unsuccessful.Most likely I’m doing something wrong but I have no idea what that is.I’ve attached a little test program that fails with the errors:[0]PETSC ERROR: - Error Message ---
I am not sure what you are asking exactly but I think so, so long have you
have called MatSetLocalToGlobalMapping() and the "stencil" idea makes sense for
your discretization.
Barry
> On Jul 28, 2022, at 5:41 PM, Randall Mackie wrote:
>
> Dear PETSc users:
>
> Can one use a MatPreall
Dear PETSc users:
Can one use a MatPreallocator and then call MatPreAlloctorPreallocate if using
MatStencil routines (which seem to call MatSetValuesLocal).
Thanks, Randy
