def ex632(): n = 2**8 rule = 110 ratio = 2 ca = CA(rule, n, ratio = ratio) #ca.start_random() m = ratio * n / 2 ca.array[0, m-1] = 1 ca.array[0, m] = 1 for i in range(20): ca.array[0, m+i] = 1 ca.start_single() ca.loop(n-1) return ca
def fractal_dim(ca_rule, t = 100, plot = True):
""" plot box counting dimension and return estimated dimension"""
ca = CA(ca_rule, t)
ca.start_single()
Ns = [1]
drawer = PyplotDrawer()
for i in range(t-1):
ca.step()
Ns.append(sum(ca.array[ca.next-1]))
Ns = np.cumsum(Ns)
one_over_eps = range(1, ca.n + 1)
dim, _ = np.polyfit(np.log(one_over_eps), np.log(Ns), 1)
if (plot):
pyplot.plot(one_over_eps, Ns)
scale = 'log'
pyplot.xscale(scale)
pyplot.yscale(scale)
pyplot.title('')
pyplot.xlabel('1/eps')
pyplot.ylabel('N(eps)')
pyplot.show()
drawer.draw(ca)
drawer.show()
return dim