python odeint keeps giving me size of array error

[j.crater]

According to error message, it seems like the array sizes aren't matching

# line 18:
return array([state0, state1]) # array of size 2

# line 35:
psi0 = np.array([0,1,1,0]) # array of size 4

# line 28:
psi = odeint(SE, psi0, x) 
# array returned by SE (line 18) and psi0 should probably be of same size

And looking at the original code, the author has psi0 of size 2.