HYPRE with multiple variables

[Shaman Mahmoudi]

Hi,

int HYPRE_BoomerAMGSetNumFunctions (.....)

sets the size of the system of PDEs.

With best regards, Shaman Mahmoudi

On Apr 13, 2007, at 2:04 PM, Shaman Mahmoudi wrote:

> Hi Nicolas,
>
> You are right. hypre has changed a lot since the version I used.
>
> I found this interesting information:
>
> int HYPRE_BOOMERAMGSetNodal(....)
>
> Sets whether to use the nodal systems version. Default is 0.
>
> Then information about smoothers:
>
> One interesting thing there is this,
>
> HYPRE_BoomerAMGSetDomainType(....)
>
> 0 - each point is a domain (default)
> 1 each node is a domain (only of interest in systems AMG)
> 2 ....
>
> I could not find how you define the nodal displacement ordering.  
> But it should be there somewhere.
>
> I read the reference manual for hypre 2.0
>
> With best regards, Shaman Mahmoudi
>
>
> On Apr 13, 2007, at 1:40 PM, Nicolas Bathfield wrote:
>
>> Dear Shaman,
>>
>> As far as I could understand, there is a BoomerAMG’s systems AMG  
>> version
>> available. This seems to be exactly what I am looking for, but I just
>> don't know how to access it, either through PETSc or directly.
>>
>> Best regards,
>>
>> Nicolas
>>
>>> Hi,
>>>
>>> You want to exploit the structure of the model?
>>> As far as I know, boomeramg can not treat a set of rows or blocks as
>>> a molecule,  a so called block-smoother?
>>> ML 2.0 smoothed aggregation does support it.
>>>
>>> With best regards, Shaman Mahmoudi
>>>
>>> On Apr 13, 2007, at 10:45 AM, Nicolas Bathfield wrote:
>>>
>>>> Hi,
>>>>
>>>> I am solving the Navier-stokes equations and try to use Hypre as
>>>> preconditioner.
>>>> Until now, I used PETSc as non-segregated solver and it worked
>>>> perfectly.
>>>> Things got worse when I decided to use Boomeramg (Hypre).
>>>> As I solve a system of PDEs,  each cell is represented by 5 rows  
>>>> in my
>>>> matrix (I solve for 5 variables). PETSc handles that without  
>>>> problem
>>>> apparently, but the coarsening scheme of Boomeramg needs more  
>>>> input in
>>>> order to work properly.
>>>>
>>>> Is there an option in PETSc to tell HYPRE that we are dealing  
>>>> with a
>>>> system of PDEs? (something like:  -pc_hypre_boomeramg_...)
>>>>
>>>>
>>>> Thanks for your help.
>>>>
>>>> Best regards,
>>>>
>>>> Nicolas
>>>>
>>>>
>>>> --
>>>> Nicolas BATHFIELD
>>>> Chalmers University of Technology
>>>> Shipping and Marine Technology
>>>> phone: +46 (0)31 772 1476
>>>> fax:   +46 (0)31 772 3699
>>>>
>>>
>>>
>>
>>
>> -- 
>> Nicolas BATHFIELD
>> Chalmers University of Technology
>> Shipping and Marine Technology
>> phone: +46 (0)31 772 1476
>> fax:   +46 (0)31 772 3699
>>
>