[petsc-users] help needed for -snes_mf_operator

[Barry Smith]

   Dominik,

     The -snes_type test option    compares the full Jacobian you provide with one that PETSc computes to try to determine if your Jacobian is correct. Please run with this option and see what happens and send us result. It should print a few numbers and a statement of whether the Jacobian provided is correct or not.

    The option cannot be used with -snes_mf or -snes_mf_operator because the option -snes_type test is ONLY to test the computation of the Jacobin, it does not actually try to solve the system.

   Barry



On Apr 25, 2012, at 4:31 PM, Dominik Szczerba wrote:

>>   Do not pass -snes_mf or -snes_mf_operator with the -snes_type test   option
> 
> Sorry, I am lost.
> 
> I provide an analytical Jacobian to a polynomial function. Sure I can
> make mistakes even in such trivial derivations, but how would I get
> the results I expect from a book without the option?
> 
> Dominik