Half or quarter polar plots in Matplotlib?

Question

I am trying to make a polar plot that goes 180 degrees instead of 360 in Matplotlib similar to http://www.mathworks.com/matlabcentral/fileexchange/27230-half-polar-coordinat

Answer 1

The following works in matplotlib 2.1 or higher. There is also an example on the matplotlib page.
You may use a usual polar plot, ax = fig.add_subplot(111, polar=True) and confine the theta range. For a half polar plot

ax.set_thetamin(0)
ax.set_thetamax(180)

or for a quarter polar plot

ax.set_thetamin(0)
ax.set_thetamax(90)

Complete example:

import matplotlib.pyplot as plt
import numpy as np

theta = np.linspace(0,np.pi)
r = np.sin(theta)

fig = plt.figure()
ax = fig.add_subplot(111, polar=True)
c = ax.scatter(theta, r, c=r, s=10, cmap='hsv', alpha=0.75)

ax.set_thetamin(0)
ax.set_thetamax(180)

plt.show()

Answer 2

The example code in official matplotlib documentation may obscure things a little bit if someone just needs a simple quarter of half plot. I wrote a code snippet that may help someone who is not that familiar with AxisArtists here.