1 # Brownian motion -- an example of a NON multi-threaded Tkinter program ;)
2 # By Michele Simoniato, inspired by brownian.py
16 stop = 0 # Set when main loop exits
17 root = None # main window
19 def particle(canvas): # particle = iterator over the moves
21 x = random.gauss(WIDTH/2.0, SIGMA)
22 y = random.gauss(HEIGHT/2.0, SIGMA)
23 p = canvas.create_oval(x-r, y-r, x+r, y+r, fill=FILL)
25 dx = random.gauss(0, BUZZ)
26 dy = random.gauss(0, BUZZ)
28 canvas.move(p, dx, dy)
34 def move(particle): # move the particle at random time
36 dt = random.expovariate(LAMBDA)
37 root.after(int(dt*1000), move, particle)
42 canvas = Canvas(root, width=WIDTH, height=HEIGHT)
43 canvas.pack(fill='both', expand=1)
47 for i in range(np): # start the dance
48 move(particle(canvas))
54 if __name__ == '__main__':