cdf.py

import numpy as np
import matplotlib.pyplot as plt

data = np.random.randn(100)
data = np.sort(data)
cdf = (np.arange(len(data))+1.0)/len(data)
'''C.D.F.
C.D.F. is the number of points smaller then the current value.
For each value in the data, increment up by 1/len(data). 
'''

plt.figure()
plt.plot(data, cdf)
plt.show()

Cumulative distribution function.ipynb