DA periodic

[Jianing Shi]

Thanks for your reply.

> > 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?
>
> I am not sure what boundary conditions you mean. If it is
> periodic,
> there should be no conditions on that boundary.

Well, you are right, not "boundary condition".  I was thinking about
some short-range interactions between grid points.  What I really
meant is actually handling the iteractions on the boundary, which
should be wrapped around periodically.  I can implement that by
hand, though just checking if there was something built-in already.

Jianing