[petsc-users] CG or GMRES

[Zhenglun (Alan) Wei]

I understand now. Thank for your answer.

best, :)
Alan

> Alan <zhenglun.wei at gmail.com> writes:
>
>> Thanks, Dr. Knepley,
>>       Can I treat AMG and MG like this way. To solve problems with 
>> non-symmetric matrices, MG needs users to provide the coarse mesh 
>> information. This take more complexity on coding than using AMG; but MG, 
>> generally, do better job than MG for non-symmetric problems.
> It's hard to generalize.  FAS multigrid with conservative
> discretizations and element agglomeration is popular for
> transport-dominated problems like steady-state transonic flows.  Other
> geometric MG schemes could perform worse than a given algebraic
> multigrid.