[petsc-users] Field split questions

[Colin McAuliffe]

Thanks I will look into DM. Is PCFieldSplitGetSubKSP in petsc version  
3.1p8 callable from fortran? I am getting the following error when I  
compile the fortran code, and I cant figure out if this is an error in  
my code or what.

Undefined symbols for architecture x86_64:
   "_pcfieldsplitgetsubksp_", referenced from:
       _umacr6_ in umacr6.o
ld: symbol(s) not found for architecture x86_64


thanks
Colin


Quoting Matthew Knepley <knepley at gmail.com>:

> On Wed, Aug 8, 2012 at 8:48 AM, Colin McAuliffe <cjm2176 at columbia.edu>wrote:
>
>> Hello all,
>>
>> When using PCFieldSplitSetIS to define splits within splits, should the IS
>> contain indices in the original matrix or in the next highest split level?
>>
>
> The next highest split level. You might consider using a DM if you have
> some structure (like discretization on a mesh).
> This should handle all the index-wrangling for you. It is new, but intended
> for just this kind of thing.
>
> Also, my matrix is in aij format but one of the sub fields has a block
>> diagonal structure. Is it still possible use block jacobi on this field?
>>
>
> Yes.
>
>    Matt
>
>
>> Thanks and all the best
>> 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
>



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