Periodic Boundary

Question

Hi dear all!
I want to solve
$-\nabla k \nabla u = f$ in unit square $S \in R^2$
and periodic boundary condition on $\partial S$

What do I have to do to construct periodic boundary? I found PeriodicBoundaryComputation but I do not understand how it works.

Could someone suggest me how to write the code for periodic boundary? (I've seen the examples but I hope there is a simple way of periodic boundary definition)

Thanks for help!

Comments

Hi,
take a look to the next pair of related questions:

• How to apply boundary conditions on subdomains in Fenics
• Periodic boundaries and mixed formulation of poisson equation