Scatter animations with colormaps

Hi all,

I'm trying to animate scatter plots on Matplotlib 1.2.1.
My code is as below:

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
import matplotlib.animation as anm

x = np.array([np.cos(i) for i in np.arange(0.0, 360.0, 9.0) / 180.0 * np.pi])
y = np.array([np.sin(i) for i in np.arange(0.0, 360.0, 9.0) / 180.0 * np.pi])
z = np.arange(0.0, 1.0, 0.025)

cdict = {
  'red': (
  (0.0, 0.0, 0.0),
  (0.5, 0.5, 0.5),
  (1.0, 1.0, 1.0)
  ),
  'green': (
  (0.0, 0.0, 0.0),
  (0.5, 0.0, 0.0),
  (1.0, 0.0, 0.0)
  ),
  'blue': (
  (0.0, 0.0, 0.0),
  (0.5, 0.0, 0.0),
  (1.0, 0.0, 0.0)
  )
}
my_cmap = mpl.colors.LinearSegmentedColormap('my_colormap', cdict, 256)

fig = plt.figure()
ax = fig.add_subplot(111)

def init():
  sct.set_offsets(([], []))

def update_sct(i, sct):
  sct.set_offsets((x[i], y[i]))
  return sct

sct = ax.scatter([], [], marker = 'o', s = 10.0, linewidth = 1.0, cmap = my_cmap, c = [])
sct_anm = anm.FuncAnimation(fig, update_sct, fargs = (sct,), interval = 100, frames = len(x))
ax.set_xlim((-2.0, 2.0))
ax.set_ylim((-2.0, 2.0))
plt.show()

Now I'm trying to set scatters' colors mapped by 'z'.
How can I set scatters' c values in each frame?

Magician