Adding a grid

When preparing graphics, we might need to have a quick guess of the coordinates of any part of a figure. Adding a grid to the figure is a natural way to improve the readability of a figure. In this recipe, we are going to see how to add a grid to a figure.

How to do it...

matplotlib's grid functionality is controlled with the pyplot.grid() function.

import numpy as np
import matplotlib.pyplot as plt

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

plt.plot(X, Y, c = 'k')
plt.grid(True, lw = 2, ls = '--', c = '.75')
plt.show()

This script will show a curve with a grid in the background. The grid is aligned to the ticks of the axes' legend as shown in the following graph:

How it works...

Adding a grid is as simple as calling the pyplot.grid() function with True as the argument. A grid is comprised of lines and as such, pyplot.grid() accepts line style parameters, such as linewidth, linestyle, or color. These parameters will apply to the lines used to draw the...