[petsc-users] Solving Poisson equation with multigrid

[Michele Rosso]

Hi,

I am successfully using PETSc (v3.3) in parallel to solve the Poisson 
equation in 3D . The discretization is done by using finite difference 
on a uniform structured grid.
So far I used the conjugate gradient method, but I would like to give a 
try to  multigrid.
The documentation describes multigrid as a preconditioner only, thus I 
would like to know if it is possible to use multigrid as a solver and, 
if so, if you could give my some tips to start. I am using the DMDA 
context to define matrix and vectors and my code is written Fortran.

Thank you,
Michele