animate random walkers

src/3_drude_model.md

@@ -39,7 +39,7 @@ a = 1 # acceleration
 dt = .1 # infinitesimal
 T = 20 # simulation time 
 
-v = np.zeros((2, int(T // dt), walker_number), dtype=float) # 
+v = np.zeros((2, int(T // dt), walkers), dtype=float) # 
 
 scattering_events = np.random.binomial(1, dt/tau, size=v.shape[1:])
 angles = np.random.uniform(high=2*np.pi, size=scattering_events.shape) * scattering_events