[petsc-users] Field split questions

[Barry Smith]

   Colin,

    I'm sorry we never had a FORTRAN interface for this routine. You'll need to switch to petsc-dev http://www.mcs.anl.gov/petsc/developers/index.html to use that function.

    Barry


On Aug 8, 2012, at 7:54 PM, Colin McAuliffe <cjm2176 at columbia.edu> wrote:

> 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