[petsc-users] AMG Variable block preconditioner

[Stefano Zampini]

Marco,

you should define what do you mean by "AMG block preconditioning"; separate
AMG on each block? What operator do you plan to precondition?
AFAIK, MatSetVariableBlockSizes is just exploited by the Jacobi solver .

Thanks
Stefano

Il giorno lun 28 ott 2019 alle ore 19:05 Marco Cisternino via petsc-users <
petsc-users at mcs.anl.gov> ha scritto:

> Hello everybody.
> We would like to setup an algebraic multi-grid block preconditioner and I
> would like to be able to define custom blocks of variable sizes. Reading
> the documentation, it seems that this can be achieved using the "PCGAMG"
> preconditioner and defining the blocks with the function
> "MatSetVariableBlockSizes". Is this correct?
> Are the variable blocks exploited by PCGAMG algorithms? We suppose this PC
> structure is already exploited in PCVPBJACOBI.
> Are the different options like PCHYPRE (setting "-pc_hypre_type" to
> "boomeramg") suitable for AMG preconditioner with variable size blocks?
> If none of the above solutions are available, could anyone suggest any
> other strategy in order to get a preconditioner like this using PETSc?
> Any help is much appreciated.
> Thanks.
>
> Best regards,
>
> Marco Cisternino



-- 
Stefano
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