[petsc-users] Does petsc4py support matrix-free iterative solvers?

[Eric Hester]

Is there a similar example of how to create shell preconditioners using petsc4py?

Thanks,
Eric

> On Mar 13, 2023, at 09:37, Eric Hester <eric.w.hester at icloud.com> wrote:
> 
> Ah ok. I see how the poisson2d example works. Thanks for the quick reply.
> 
> Eric
> 
>> On Mar 13, 2023, at 08:10, Jose E. Roman <jroman at dsic.upv.es> wrote:
>> 
>> Both ode/vanderpol.py and poisson2d/poisson2d.py use shell matrices via a mult(self,mat,X,Y) function defined in the python side. Another example is ex3.py in slepc4py.
>> 
>> Jose
>> 
>> 
>> 
>>> El 13 mar 2023, a las 15:58, Eric Hester via petsc-users <petsc-users at mcs.anl.gov> escribió:
>>> 
>>> Hello everyone,
>>> 
>>> Does petsc4py support matrix-free iterative solvers (as for Matrix-Free matrices in petsc)?
>>> 
>>> For context, I have a distributed matrix problem to solve. It comes from a Fourier-Chebyshev Galerkin discretisation. The corresponding matrix is dense, but it is fast to evaluate using fftw. It is also distributed in memory.
>>> 
>>> While I’ve found some petsc4py tutorial examples in "/petsc/src/binding/petsc4py/demo/“, they don’t seem to show a matrix free example. And I don’t see a reference to a matrix shell create method in the petsc4py api.
>>> 
>>> If petsc4py does support matrix free iterative solvers, it would be really helpful if someone could provide even a toy example of that. Serial would work, though a parallelised one would be better.
>>> 
>>> Thanks,
>>> Eric
>>> 
>>> 
>> 
>