Hi all,

So apparently I was somehow lucky when the below worked. If I use a 
different mesh, for example as in ex6 under systems_of_equations, the 
options below do not work. I get the error:

[0]PETSC ERROR: Nonconforming object sizes!
[0]PETSC ERROR: Index set does not match blocks!

I've tried different petsc versions (also the most recent) and there's 
no difference. It does not seem to matter whether the mesh is 
libmesh-generated or not (the mesh for which the options below work is a 
cubit-generated exodus mesh, but I also have cubit-generated exodus 
meshes for which it doesn't work. I've not been able to identify what 
causes the error).

Any ideas?


Best,
Jens




On 06/24/2013 09:10 PM, Cody Permann wrote:
> Sent from my iPhone
>
> On Jun 24, 2013, at 12:51 PM, Jens Lohne Eftang <[email protected]> wrote:
>
>> On 06/24/2013 09:18 AM, Jens Lohne Eftang wrote:
>>> Do you know if I somehow have to tell hypre that I am solving a vector
>>> problem (I'm guessing otherwise it would not be able to exploit the
>>> elliptic structure)?
>>>
>>> Jens
>> So I'm now doing this:
>>
>> mpirun -np 8 ./elasticity-opt --node_major_dofs -ksp_type cg -pc_type
>> fieldsplit -pc_fieldsplit_block_size 3 -fieldsplit_pc_type hypre
>> -fieldsplit_pc_hypre_type boomeramg
>> -fieldsplit_pc_hypre_boomeramg_strong_threshold 0.7
>> -ksp_converged_reason -pc_fieldsplit_0 0,1,2 -ksp_atol 1e-6 -log_summary
>> -ksp_monitor -pc_fieldsplit_type symmetric_multiplicative
>>
>> where I believe the idea is to use a block Jacobi preconditioner first,
>> but where there are only three blocks that correspond to each of the
>> three fields, and then within each block we apply AMG. This reduced the
>> number of iterations from 1000+ to 71.
>>
>> Memory consumption is still an issue though as this requires close to
>> 128Gb, so if anyone has experience with large problems like this and
>> ideas on how to reduce memory footprint that would be appreciated.
>>
>> One question for ParallelMesh: will this work by just changing Mesh to
>> ParallelMesh?
>>
> Actually, this is a configure-time option, --enable-parmesh.  If you
> haven't explicitly used SerialMesh in your code, you should be good to
> go.
>
> Cody
>
>> Thanks,
>> Jens
>>
>> ------------------------------------------------------------------------------
>> This SF.net email is sponsored by Windows:
>>
>> Build for Windows Store.
>>
>> http://p.sf.net/sfu/windows-dev2dev
>> _______________________________________________
>> Libmesh-users mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/libmesh-users


------------------------------------------------------------------------------
See everything from the browser to the database with AppDynamics
Get end-to-end visibility with application monitoring from AppDynamics
Isolate bottlenecks and diagnose root cause in seconds.
Start your free trial of AppDynamics Pro today!
http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk
_______________________________________________
Libmesh-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/libmesh-users

Reply via email to