Controlling a fill pattern

matplotlib offers fairly limited support to fill surfaces with a pattern. For line patterns, it can be helpful when preparing figures for black-and-white prints. In this recipe, we are going to look at how we can fill surfaces with a pattern.

How to do it...

Let's demonstrate the use of fill patterns with a bar chart as follows:

import numpy as np
import matplotlib.pyplot as plt

N = 8
A = np.random.random(N)
B = np.random.random(N)
X = np.arange(N)

plt.bar(X, A, color = 'w', hatch = 'x')
plt.bar(X, A + B, bottom = A, color = 'w', hatch = '/')

plt.show()

The preceding script produces the following graph:

How it works...

Rendering function filling volumes, such as pyplot.bar(), accept an optional parameter, hatch. This parameter can take the following values:

• /

• \

• |

• -

• +

• x

• o

• O

• .

• *

Each value corresponds to a different hatching pattern. The color parameter will control the background color of the pattern, while the edgecolor parameter will control the color of the hatching.