increase radius of a single sector in pie chart matplotlib

Question

I am new to matplotlib pie charts and I want to know how we can set the radius of a single sector in pie chart. I know about how to set the overall radius of the chart, but want to increase the radius of a single sector. For example, in this picture, sector '1' is with grater radius as compared to others. Please note that: I don't want to explode that sector for increasing radius.

Please tell me if someone knows! Thanks in advance.

Answer 1

The direct answer is that it doesn't appear to be possible with Matplotlib to set multiple radii within the same pie plot.

#! /usr/bin/env python
# -*- coding: utf-8 -*-

import matplotlib.pyplot as plt

data = [4, 3, 2, 1]

fig, ax = plt.subplots(figsize=(4,4))

wedges, texts = ax.pie(data, radius=1)

for w in wedges:
    w.set_width(.5)

wedges[0].set_radius(1.1)
wedges[1].set_radius(1)
wedges[2].set_radius(1)
wedges[3].set_radius(1)

plt.show()

radii = [w.radius for w in wedges]
print(radii)

We can see that the radii are, in fact, different.

[1.1, 1, 1, 1]

But Different Radii Don't Appear to be Different

An interesting side note is that slice widths can be different:

Slices with Different Widths

Another Way

However, you can work around this with a little bit of sleight of hand. Instead of plotting one pie plot, you plot two--the first with the "enlarged" slice invisible and the second plot with the "enlarged" slice set as the only visible slice.

#! /usr/bin/env python
# -*- coding: utf-8 -*-

import matplotlib.pyplot as plt

data = [4, 3, 2, 1]

fig, ax = plt.subplots(figsize=(4,4))

# Pie 1
wedges, texts = ax.pie(data, radius=1)

for w in wedges:
    w.set_width(.5)

wedges[0].set_visible(False)

# Pie 2
wedges1, texts1 = ax.pie(data, radius=1.1)

for w in wedges1:
    w.set_width(.6)

wedges1[1].set_visible(False)
wedges1[2].set_visible(False)
wedges1[3].set_visible(False)

plt.show()

Example of Pie Plot with Enlarged Slice

The set_width arguments are added to make the plot a "donut" plot like your example. Note the width values in each chart that are required to achieve the desired look.