import trtools.charting.api as charting
from pandas.io.data import DataReader
import datetime
import pandas as pd

sp500 = DataReader("^GSPC", "yahoo", start=datetime.datetime(1990, 1, 1))

ma30 = pd.rolling_mean(sp500.Close, 30)
ma90 = pd.rolling_mean(sp500.Close, 90)

crossover = (ma30 > ma90).diff() > 0

fig = charting.Figure(1)
sp500.tail(300).ohlc_plot()
ma30.fplot()
ma90.fplot()
fig.plot_markers('crossover', crossover, yvalues=ma30)