[petsc-users] How to use multigrid?

[A.L. Siahaan]

Thank's a lot, Mark ! What does 'native' mean here ? That it is PETSc's 
built-in and not interface ?

Antony

On Nov 9 2012, Mark F. Adams wrote:

>> Of all algebraic multigrid implemented or interfaced in PETSc, i.e. 
>> BoomerAMG (PCHypre), ML(PCML), and PCGAMG("agg"), what is the order of 
>> the cost (memory) to set up the preconditioner (setting nullspace etc) ?
>
> Not a simple question. ML and GAMG use very similar algorithms and ML is 
> implemented in a more "native" way than hypre (GAMG is completely 
> native). GAMG/ML are probably better for elasticity, hypre is great for 
> 2D low order discretizations of Laplacian, and it is a very hardened 
> implementation. hypre is not native so there are some things that don't 
> work as well.
>
>> 
>> Regards,
>> Antony
>>