Trend indicator sample

mv.py

import matplotlib.pyplot as plt

def SMA(df, s, l):
    df["sma"] = df.Close.rolling(window=s).mean()
    df["lma"] = df.Close.rolling(window=l).mean()
    df["diff"] = df.sma - df.lma

    xdate = [x.date() for x in df.index]
    plt.figure(figsize=(15, 5))
    plt.plot(xdate, df.Close, label="close")
    plt.plot(xdate, df.sma,label="short")
    plt.plot(xdate, df.lma,label="long")
    plt.xlim(xdate[0], xdate[-1])
    plt.grid()

    # Cross points
    for i in range(1, len(df)):
        if df.iloc[i-1]["diff"] < 0 and df.iloc[i]["diff"] > 0:
            print("{}:GOLDEN CROSS".format(xdate[i]))
            plt.scatter(xdate[i], df.iloc[i]["sma"], marker="o", s=100, color="b", alpha=0.9)

        if df.iloc[i-1]["diff"] > 0 and df.iloc[i]["diff"] < 0:
            print("{}:DEAD CROSS".format(xdate[i]))
            plt.scatter(xdate[i], df.iloc[i]["sma"], marker="o", s=100, color="r", alpha=0.9)

    plt.legend()