Re: [petsc-dev] How does PETSc define the overlap in an algebraic ASM preconditioner ?

2022-04-12 Thread Matthew Knepley
On Tue, Apr 12, 2022 at 4:14 AM markwinpe wrote: > Dear PETSc’s developers, > > Currently, I don’t have a geometric mesh for a PDE problem, I just > got a matrix from others and I want to use the ASM preconditioner to solve > the linear system. I would be appreciated if you could describe ho

Re: [petsc-dev] How does PETSc define the overlap in an algebraic ASM preconditioner ?

2022-04-12 Thread Mark Adams
You can see https://petsc.org/main/docs/manualpages/PC/PCASM.html It is very simple as you can see but you are limited to one block per MPI process. If you want more then you need to create them and use https://petsc.org/main/docs/manualpages/PC/PCASMSetLocalSubdomains.html#PCASMSetLocalSubdomains

[petsc-dev] How does PETSc define the overlap in an algebraic ASM preconditioner ?

2022-04-12 Thread markwinpe
Dear PETSc’s developers, Currently, I don’t have a geometric mesh for a PDE problem, I just got a matrix from others and I want to use the ASM preconditioner to solve the linear system. I would be appreciated if you could describe how PETSc defines the overlap in the context of using the al