bars.values[1].plot(ax=ax1, color='r', lw=2.)

# Plot two charts to assess trades and equity curve
fig = plt.figure()
fig.patch.set_facecolor('white')     # Set the outer colour to white
ax1 = fig.add_subplot(211,  ylabel='Price in $')

# Plot the AAPL closing price overlaid with the moving averages
bars.values[1].plot(ax=ax1, color='r', lw=2.)
signals[['short_mavg', 'long_mavg']].plot(ax=ax1, lw=2.)

# Plot the "buy" trades against AAPL
ax1.plot(signals.ix[signals.positions == 1.0].index,
         signals.short_mavg[signals.positions == 1.0],
         '^', markersize=10, color='m')

# Plot the "sell" trades against AAPL
ax1.plot(signals.ix[signals.positions == -1.0].index,
         signals.short_mavg[signals.positions == -1.0],
         'v', markersize=10, color='k')