Submesh / FunctionSpace for subdomain

[bagla0]

UPDATE

I am able to generate the submesh and get stress plot for each submesh domain seperately.
How can I merge these plots (using hold on feature similar to matlab)?

# stress Plot
Vf = FunctionSpace(submesh_fib, 'DG', 0)
Vm = FunctionSpace(submesh_mat, 'DG', 0)
sigf=project(sigma_vec(v,1,Eps)[0],Vf)
sigm=project(sigma_vec(v,0,Eps)[0],Vm)

plt.figure()
p1 = plot(sigm)
plt.colorbar(p1)
plt.show()


plt.figure()
p2 = plot(sigf)
plt.colorbar(p2)
plt.show()
![fib|569x451](upload://xk57ZBprNVpqXI9bTeojdL3vrPd.png)

I tried FunctionAssigner, but getting error in interpolate step according to

@Nico_Su

T = FunctionSpace(mesh, 'CG', 2)

v = Function(V)

S_1 = Function(S)
S_11, S_12 = S_1.split()

T_S_1 = interpolate(S_11, T)
T_S_2 = interpolate(S_12, T)
#next line results in an error
assigner = FunctionAssigner(V, [T, T])
assigner.assign(v, [T_S_1, T_S_2])