[petsc-users] help needed for -snes_mf_operator

[Barry Smith]

   Do not pass -snes_mf or -snes_mf_operator with the -snes_type test   option

   Barry

On Apr 25, 2012, at 4:16 PM, Jed Brown wrote:

> On Wed, Apr 25, 2012 at 16:06, Dominik Szczerba <dominik at itis.ethz.ch> wrote:
> I am happy to be guilty if I know how I can improve: why do I get the
> right results without this option, for several cases?
> 
> How do you define "right results"? Is SNES converging quadratically when you do not use -snes_mf_operator?
>  
> 
> > Run with -snes_type test and see what it reports.
> 
> The moment I specify this option I get:
> 
> [0]PETSC ERROR: Invalid argument!
> [0]PETSC ERROR: Cannot test with alternative preconditioner!
> 
> tracing back to SNESSolve()
> 
> You either (a) set different matrices for the operator and preconditioning matrix or (b) passed -snes_mf. Just pass one matrix.