Presenting both closing price and trading volume

Sometimes, we like to view both price movement and trading volumes simultaneously. The following program accomplishes this:

>>>from pylab import plotfile, show
>>>import matplotlib.finance as finance
>>>ticker = 'IBM'
>>>begdate = datetime.date(2013,1,1)
>>>enddate = datetime.date.today()
>>>x= finance.fetch_historical_yahoo(ticker, begdate, enddate)
>>>plotfile(x, (0,6,5))
>>>show()

The output graph is shown as follows:

Adding mathematical formulae to our graph

In finance, we use many mathematical formulae. Occasionally, we need to add a mathematical formula to our figure. A set of formulae for a call option by using the matplotlib module is shown in the following program:

import numpy as np
import matplotlib.mathtext as mathtext
import matplotlib.pyplot as plt
import matplotlib
matplotlib.rc('image', origin='upper')
parser = mathtext.MathTextParser("Bitmap")
r'$\left[...