Hello,
I am given the equation: find $u$ which fulfills for a given $f$:
$$ u-\Delta f = 0 $$
On the boundary, we have homogeneous Neumann conditions. So, in my ufl I write:
P1 = FiniteElement("Lagrange", triangle, 1)
u = TrialFunction(P1)
u_t = TestFunction(P1)
f = Coefficient(P1)
a = u*u_t*dx
L = f*u_t*dx
forms = [a,L]
Then, in my c++ code, I write:
Form_a a(V,V);
Form_L L(V);
L.set_coefficient("f",f);
solve(a == L, *u)
where $f$ and $u$ are of type
std::shared_ptr<dolfin::Function>
Unfortunately, this does not work. Can anyone find a mistake or has a simpler solution?
I would be grateful for any help.
frieder
