s = \laplace \phi (if \phi is known, how to solve s in FeniCS form)

Question

Hi,
I have a question as follow,
The demo told us how to solve Poisson equations. However, what should i do in the grammar of FeniCS to solve s = \laplace \phi, where \phi is known.

Answer 1

Well, It woks:
laplace_phi = phi_i.dx(0).dx(0) + phi_i.dx(1).dx(1)
pro_lap_phi = project(laplace_phi,Mh)

Comments

however, it can not wok out in loop ? Could anyone tell me how to implement? Thanks a lot