Compute the product of two dolfin::Function (s)

Question

Hi!
I have given a dolfin::Function , let's name it u.
Now I would like to compute N(u) = u^3. Is this possible and how?

I am programming in c++

I am very thankful for any help.
frieder

Answer 1

You can do it by defining a Form in ufl
e.g.

v = TestFunction(FE)
u = Coefficient(FE)
N = TrialFunction(FE)
a = u**3*v*dx
F = N*v*dx

Then you assign your 'u' to 'a' and solve a == F for your function N.