[petsc-users] Field split questions

[Matthew Knepley]

On Wed, Aug 8, 2012 at 10:23 PM, Colin McAuliffe <cjm2176 at columbia.edu>wrote:

> Thanks all, regarding use of DM in 3.3, is the procedure now to create the
> fields with PCFieldSplitSetIS and then use DMCreateFieldDecompositionDM to
> create a new DM based from the new fields and the DM for the original
> problem?
>

1) Use petsc-dev

2) PCFieldSplitSetIS() is independent. This allows you to define splits
however you want, but then recursive gets harder

3) In 3.3., it uses DMCreateFieldDecompositionDM() to split all fields
apart at once

4) In petsc-dev, it uses DMCreateSubDM() which can split off any
combination of fields, which from the command line is something like

     -pc_fieldsplit_0_fields 2,0 -pc_fieldsplit_1_fields 1,3

     Matt


> Colin
>
> --
> Colin McAuliffe
> PhD Candidate
> Columbia University
> Department of Civil Engineering and Engineering Mechanics
>



-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120808/52d392f9/attachment.html>