How to modify a PDE solution in dolfin-FEniCS

Question

Hello: I need to change the form of a PDE solution in fenics,

All PDE can be expressed in like this:

$La = b$

and solve in this way:

a = .... #bilinear form
L = .... #linear form
V = .... #function space
bc = DirichletBC(V, psi0, psi0_boundary)
psi = Function(V)
solve(a == L, psi, bc)

But in this part I need to change the $\psi$ value to other funcion with the next transformation

$\psi_2 = \psi/norm(grad(\psi))$

Some one know how to get this new funcion since psi in FEniCS?

Answer 1

Hi, see if you are happy with the following

grad_norm = norm(psi, 'h10')
psi0 = project(psi/grad_norm, V, bcs=bc)