[petsc-users] What does PCASMSetOverlap do?

[Mark Adams]

No, without overlap you have, let say:
core 1:   1:32, 1:32
core 2:   33:64,  33:64

Overlap will increase the size of each domain so you get:
core 1:   1:33, 1:33
core 2:   32:65,  32:65

What you want is reasonable but requires PETSc to pick a separator set,
which is not well defined.
You need to build that yourself with gasm (I think) if you want this.

Mark

On Wed, Apr 13, 2022 at 3:17 AM Zhuo Chen <chenzhuotj at gmail.com> wrote:

> Hi,
>
> I hope that everything is going well with everybody.
>
> I have a question about the PCASMSetOverlap. If I have a 128x128 matrix
> and I use 4 cores with overlap=1. Does it mean that from core 1 to core 4,
> the block ranges are (starting from 1):
>
> core 1:   1:33, 1:33
> core 2:   33:65,  33:65
> core 3:   65:97,  65:97
> core 4:   95:128, 95:128
>
> Or is it something else? I cannot tell from the manual.
>
> Many thanks in advance.
>
>
>
> --
> Zhuo Chen
> Department of Astronomy
> Tsinghua University
> Beijing, China 100084
> *https://czlovemath123.github.io/ <https://czlovemath123.github.io/>*
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20220413/23b3de6e/attachment.html>