[petsc-users] SetOptionsPrefix

[Jed Brown]

Dharmendar Reddy <dharmareddy84 at gmail.com> writes:
> Hello,
>          I was wondering how the <SENS,KSP,PC>SetOptionsPrefix work ?. I
> can figure out from the code that SNES set options prefix sets the options
> prefix to the ksp and pc objects on snes. Does it also apply the prefix to
> the Matrix and vectors passed to snes as jacobian, function and solution?
> or, are they considered as a independent objects ? Do i need to set options
> prefix to matrix and vector objects pased to snesset jacobian and snesset
> function.

They are separate objects, but a prefix is automatically added to any
(configurable) objects created internally by the solvers, including
nested solvers.

If you want a unique prefix for the Jacobian, the preconditioning matrix
(Pmat), or specific vectors, you should set it.