What are n bins and patches in matplotlib?

Question

I read this in the matplotlib tutorial:

n, bins, patches = plt.hist(x, 50, normed=1, facecolor='g', alpha=0.75)

I am wondering what are n, bins, and patches

Answer 1

I was going to suggest reading the docs but this provides no extra explanation although I still advise you have a look.

• n: is the number of counts in each bin of the histogram
• bins: is the left hand edge of each bin
• patchesis the individual patches used to create the histogram, e.g a collection of rectangles

The patches can be used to change the properties of individual bars as in these examples. Here is a simple example of its use

import numpy as np
import matplotlib.pyplot as plt
x = np.random.normal(size=100)
n, bins, patches = plt.hist(x)

plt.setp(patches[0], 'facecolor', 'g')
plt.show()

In general the n and bins are used for subsequent data analysis as in this demo