Bug report

Bug summary

The default configuration for pie charts should give circular pies. That is in the definition according to Wikipedia:

A pie chart (or a circle chart) is a circular statistical graphic which is divided into slices to illustrate numerical proportion.

See for example: https://kosara.net/papers/2016/Kosara-EuroVis-2016.pdf

Code for reproduction

import matplotlib.pyplot as plt

plt.pie([10, 90])
plt.show()

Actual outcome

Expected outcome

The expected outcome is the following

This is obtained by the following snippet

import matplotlib.pyplot as plt

plt.pie([10, 90])
plt.axis("image")
plt.show()

Matplotlib version

• Operating system: Linux Mint
• Matplotlib version: 2.1.2
• Matplotlib backend (print(matplotlib.get_backend())): Qt5Agg
• Python version: 3.6.4
• Distribution: Anaconda custom (64-bit)| (default, Jan 16 2018, 18:10:19)