How to set the axis limit in a matplotlib plt.polar plot

Question

Say I have the following polar plot:

a=-0.49+1j*1.14
plt.polar([0,angle(x)],[0,abs(x)],linewidth=5)

And I'd like to adjust the radial limits to 0 to 2.

What is the best way to do this?

Note that I am asking specifically about the plt.polar() method (as opposed to using polar=True parameter in a normal plot common in similar questions).

This seems to work, unless I'm plotting from the console (Spyder, Win7):

>>> ax=plt.gca()
>>> ax.set_rlim(0,2)

Solution 1

You can just use the classic method

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(-180.0,190.0,10)
theta = (np.pi/180.0 )*x    # in radians

offset = 2.0

R1 = [-0.358,-0.483,-0.479,-0.346,-0.121,0.137,0.358,0.483,0.479,0.346,0.121,\
-0.137,-0.358,-0.483,-0.479,-0.346,-0.121,0.137,0.358,0.483,0.479,0.346,0.121,\
-0.137,-0.358,-0.483,-0.479,-0.346,-0.121,0.137,0.358,0.483,0.479,0.346,0.121,\
-0.137,-0.358]

fig1 = plt.figure()
ax1 = fig1.add_axes([0.1,0.1,0.8,0.8],polar=True)
ax1.set_ylim(-2,2)
ax1.set_yticks(np.arange(-2,2,0.5))
ax1.plot(theta,R1,lw=2.5)
plt.show()

Solution 2

An easier approach to solve the OP may be:

ax.set_ylim([0,2])

Comments

[Eric Duminil]

Thanks. It's good to know that it works. But... why? In a polar plot, I wouldn't expect y to be defined. Also, what's the point of rlim, then?