Adding such annotations is very simple, as demonstrated in the following example:

import numpy as np
import matplotlib.pyplot as plt

X = np.linspace(-4, 4, 1024)
Y = .25 * (X + 4.) * (X + 1.) * (X - 2.)

plt.title('Power curve for airfoil KV873')
plt.xlabel('Air speed')
plt.ylabel('Total drag')

plt.plot(X, Y, c = 'k')
plt.show()

The figure will be the same as the one obtained in the first recipe of this chapter. However, both the axes will feature a legend.

We use the pyplot.xlabel() and pyplot.ylabel()functions to add a description of the horizontal axis and the vertical axis, respectively. As for the pyplot.title() function, this function accepts the LaTeX notation. These functions are available for any kind of graphic; you would use the same...