Interactive navigation toolbar

If you have tried some of the book examples proposed so far, then you may have already noticed the interactive navigation toolbar (because when using matplotlib.pyplot, the toolbar is enabled by default for every figure), but in any case, here is a screenshot of the window:

This window pops up with the following code, when executed in IPython:

In [1]: import matplotlib as mpl
In [2]: mpl.use('GTKAgg') # to use GTK UI
In [3]: import matplotlib.pyplot as plt
In [4]: plt.plot([1, 3, 2, 4])
Out[4]: [<matplotlib.lines.Line2D object at 0x909b04c>]
In [5]: plt.show()

It's worth taking the time to learn more about this window, since it provides basic elaboration and manipulation functions for interactive plotting.

First of all, note how passing the mouse over the figure area results in the mouse pointer's coordinates being shown in the bottom-right corner of the window.

At the bottom of the window, we can find the navigation toolbar. A description of each of its...