PCNN preconditioner

[Andreas Grassl]

Ok, this would be easy. I didn't try it, because I was thinking, that I have to
mess around with more ISLocalToGlobal-stuff.

I'll try out and give a feedback.

cheers

ando

Barry Smith schrieb:
> 
>     I'm sorry there is no example of the use of PCNN. Here is what you
> need to do.
> Use MatCreateIS() to create the matrix. Use MatSetValuesLocal() to put
> the values in the matrix
> then use PCSetType(pc,PCNN); to set the preconditioner to NN.
> 
>    Barry
> 
> Note: You cannot just use MatCreateMPIAIJ() to create the matrix because
> it needs the unassembled per processor parts to build the preconditioner.
> You cannot use MatSetValues() because then it could not have the
> unassembled matrix.
> 
> 
> On Feb 26, 2009, at 10:12 AM, Andreas Grassl wrote:
> 
>> Hello,
>>
>> I'm working with a FE-Software where I get out the element stiffness
>> matrices and the element-node correspondency to setup the stiffness
>> matrix for solving with PETSc.
>>
>> Currently this is working fine for the seqaij matrix type and connected
>> solvers. Now I want to Implement the PCNN preconditioner.
>>
>> Does anybody have any simple examples with this preconditioner?
>>
>> Thank you in advance
>>
>> ando
>>
>> -- 
>> /"\                               Grassl Andreas
>> \ /    ASCII Ribbon Campaign      Uni Innsbruck Institut f. Mathematik
>>  X      against HTML email        Technikerstr. 13 Zi 709
>> / \                               +43 (0)512 507 6091
> 

-- 
 /"\
 \ /      ASCII Ribbon
  X    against HTML email
 / \


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 315 bytes
Desc: OpenPGP digital signature
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090226/109f2caa/attachment.pgp>