Using -pctype mg -pcmgtype PC_MG_MULTIPLICATIVE

[Ben Tay]

Btw, is the file to download 
ftp://ftp.mcs.anl.gov/pub/petsc/externalpackages/ml-5.0.tar.gz?

Thanks

Matthew Knepley wrote:
> The multigrid PC needs information about the grid and discretization. If you
> cannot provide this, use AMG through Hypre or ML. Or if you have a
> structured grid, consider using DMMG.
>
>   Thanks,
>
>     Matt
>
> On 8/15/07, Ben Tay <zonexo at gmail.com> wrote:
>   
>> Hi,
>>
>> I found that there's a multigrid option in the manual which can be used
>> by adding -pctype mg -pcmgtype PC_MG_MULTIPLICATIVE.
>>
>> However, it seems that I am actually just using LU since with or without
>> this option, I got exactly the same answer. Am I using multigrid the
>> wrong way?
>>
>> Thanks
>>
>>
>>     
>
>
>