[petsc-users] DASetCoordinates

[Barry Smith]

On Sep 28, 2010, at 4:22 PM, Jed Brown wrote:

> On Tue, Sep 28, 2010 at 20:59, Randall Mackie <rlmackie862 at gmail.com> wrote:
>> I'm trying to use the DMMG structure to do multi-grid as a preconditioner.
>> My grids have non-uniform
>> spacing. I can compute the non-uniform spacing at each level, and I assume I
>> can get that information
>> to the multigrid solver using DASetCoordinates. I also assume that this is
>> needed to correctly compute
>> the matrices that allow you to go from one level to another. My questions
>> are:
>> 
>> 1) Where exactly should DASetCoordinates be called?
> 
> You will have to call it at every level, DARefine and DACoarsen do not
> currently interpolate coordinates.  Maybe they should?

   Sounds reasonable for them to automatically handle the coordinates if they exist.

   Barry

   The reason the coordinates are treated like second cousins is that they are second cousins and were added later and never fully integrated with the DA experience. Probably someone with energy and time on their hands could go through and integrate the coordinates more fully into the DA infrastructure.


> 
> Jed