[petsc-users] Obtaining more ghost points at EE, SS etc using DM

[TAY wee-beng]

On 15/6/2012 9:04 PM, Jed Brown wrote:
> If you need corner points, use DMDA_STENCIL_BOX.

Sorry， I don't mean corner points, but points to the east of the east 
cell, or the west of the west cell ie. instead of only 1 ghost cell to 
the east of the boundary, I need 1 more which is east of the east cell.
>
> On Fri, Jun 15, 2012 at 7:58 PM, TAY wee-beng <zonexo at gmail.com 
> <mailto:zonexo at gmail.com>> wrote:
>
>     Hi,
>
>     I'm trying to implement DM in my code. So far, I found that it is
>     very convenient to use its features. I am currently using DMDA
>     STENCIL STAR.
>
>     However, in some parts of my code, I need to update ghost points
>     at east east, west west etc.
>
>     DMGlobalToLocalBegin/end can only update east, west etc. What's
>     the easiest way to update these additional points? Do I have to
>     use MPI_Send?
>
>     Also, how is the memory allocated? I think the east east values
>     will be outside the local vector, is that so?
>
>     Thank you.
>
>     -- 
>     Yours sincerely,
>
>     TAY wee-beng
>
>
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