How to draw a histogram with variable-width bins in Python?

Question

Suppose I have data [1,2,3, 7,8,9,9, 20,30,40,100,1000] for which I want to draw a histogram with Python. All the bins I care about is [0,5], [5,10], and [10, +∞). How can I do it?

The following wouldn't do it, of course.

import matplotlib.pyplot as plt

data = [1,2,3, 7,8,9,9, 20,30,40,100,1000]
plt.figure()
plt.hist(data, bins=5, color="rebeccapurple")
plt.show()

A histogram is to show distribution. If you change the sizing of them it can be misleading. Perhaps a bar chart is more of what you're looking for? — hrokr
– hrokr, Commented Jul 15, 2020 at 5:16
Good point. Although in some cases we only need to know there's a fat tail — Paw in Data
– Paw in Data, Commented Jul 15, 2020 at 5:57
See answers there : stackoverflow.com/questions/43005462/… — Skippy le Grand Gourou
– Skippy le Grand Gourou, Commented Oct 11, 2022 at 15:45

ilkyu tony lee · Accepted Answer · 2020-07-16 02:18:39Z

2

In case of forcing to show a histogram with customized x-range, you might need to process your data first.

I made a list of ranges and also x_ticklabels to show x-axis with range.

import matplotlib.pyplot as plt
import numpy as np

data = [1,2,3, 7,8,9,9, 20,30,40,100,1000,500,200]
data = np.array(data)
bin_range = [
    [0, 5],
    [5, 10],
    [10, 10000] # enough number to cover range
]

data2plot = np.zeros(len(bin_range))

for idx, (low, high) in enumerate(bin_range):
    data2plot[idx] = ((low <= data) & (data < high)).sum()
    
fig = plt.figure()
ax = fig.add_subplot(111)
ax.bar(range(len(bin_range)), data2plot)

x_labels = [
    f"{low}~{high}" for idx, (low, high) in enumerate(bin_range)
]

ax.set_xticks(range(len(bin_range)))
ax.set_xticklabels(x_labels)
plt.show()

edited Jul 16, 2020 at 2:18

answered Jul 15, 2020 at 5:28

ilkyu tony lee

1038 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Paw in Data Over a year ago

Wow... this is bigger job than I'd expect! But using barplot is clever

ilkyu tony lee Over a year ago

@PawinData Most sophisticated job is changing x-axis labels... without that, the code can be clear and short.

JohanC Over a year ago

Just using ax.set_xticklabels without ax.set_xticks can be tricky, as they are set automatically. Better set ax.set_xticks(range(len(bin_range))) and ax.set_xticklabels(x_labels) without inserting the empty strings.

ilkyu tony lee Over a year ago

@JohanC thx. Your method is so nice. Updated answer.

Collectives™ on Stack Overflow

How to draw a histogram with variable-width bins in Python?

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related