DA periodic

[Jianing Shi]

I have a question about the usage of periodic DA.

1) In function DACreate2d( ), there is an argument about
DAPeriodicType. I assume the mentioned periodicity is for the
global array, not for local grid?

2) If I use the periodic type for DA, together with SNES to solve a
system, when I implement the FormFunctionLocal, I need to
explicitly implement the boundary conditions?  Or does DA periodic
type has some built-in functionality?

Thanks,

Jianing