[petsc-users] How to manually set the matrix-free differencing parameter h?

[Barry Smith]

   That's not really the right function; you can use MatMFFDSetFunctionError(), MatMFFDSetType(), MatMFFDSetPeriod() to set the available parameters.


    Barry


> On May 23, 2017, at 12:09 PM, Ping He <friedenhe at gmail.com> wrote:
> 
> Hi,
> 
> I am using PETSc-SNES matrix free approach, and I would like to know how to manually set the differencing parameter h. I tried to use the SNESDefaultMatrixFreeSetParameters2 function but I got an error when compiling: ‘SNESDefaultMatrixFreeSetParameters2’ was not declared in this scope.
> 
> Thanks very much in advance.
> 
> Regards,
> Ping