[petsc-users] hypre support

[Barry Smith]

On May 16, 2014, at 10:46 AM, Dario Isola <dario.isola at newmerical.com> wrote:

> Dear all,
> 
> I am investigating the use of hypre+petsc. I was able to successfully configure, install, compile petsc 3.3 with the external package for hypre.
> 
> I tried to run it with the following options
> -pc_type hypre -pc_type_hypre pilut -ksp_type richardson
> and, although he did not complain, it does not solve the system either.

   Do you meaning it did not converge? At first always run with -ksp_view (or -snes_view if using snes or -ts_view if using ts) and -ksp_monitor_true_residual to see what is going on.

> -pc_type_hypre pilut

is wrong it is -pc_hypre_type pilut

Note that pilut will generally not work with Richardson you need a “real” Krylov method like GMRES. 

Also the ilu type preconditioners don’t scale particularly well though occasionally they can be fine.

> 
> To what extent is hypre supported by petsc? More specifically, what kind of matrices?

   If it cannot handle the matrix type it would give an error message.  Hypre uses a format like AIJ so you should use AIJ. Note that you can make the matrix type a runtime option so you don’t have to compile in that it is BAIJ.


> I am using a baij matrix.
> 
> Thanks in advance,
> D