[petsc-dev] PCASM with custom overlap/local matrices

[Pierre Jolivet]

Thanks!
From:
MatCreateSubMats       1 1.0 2.2059e-01 1.1 0.00e+00 0.0 5.0e+01 1.9e+04 4.0e+00  1  0  3  0  0   1  0  3  0  0     0
to:
MatCreateSubMats       1 1.0 1.1206e-05 1.3 0.00e+00 0.0 0.0e+00 0.0e+00 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
on my laptop and four subdomains.

I guess I can expect nice gains for our Helmholtz and Maxwell solvers at scale and/or with higher order discretizations!
Pierre

> On 4 Jan 2020, at 9:17 PM, Smith, Barry F. <bsmith at mcs.anl.gov> wrote:
> 
> 
>   Can you overload the MatCreateSubMatrices() to use your function instead of the default. Using MatSetOperation()?
> 
>   Barry
> 
> 
>> On Jan 4, 2020, at 5:30 AM, Pierre Jolivet <pierre.jolivet at enseeiht.fr> wrote:
>> 
>> Hello,
>> I’d like to bypass the call to MatCreateSubMatrices during PCSetUp_PCASM because I’m using a custom (geometric) overlap (PCASMSetLocalSubdomains) and I have a direct access to the corresponding subdomain matrices with optimized boundary conditions.
>> Currently, I’m using PCSetModifySubMatrices which just overrides the local Dirichlet matrix with my own, so there is no real need for the call to MatCreateSubMatrices.
>> Do you see of a way to do this?
>> 
>> Thanks,
>> Pierre
>