Reverse radial axes of Matplotlib polar plot
astronomy, matplotlib, plot, python, reverse
Solution
It's a little bit "hacky", but if you know the bounds (which it seems like you do as it corresponds to declination) you could do something like:
import matplotlib.pyplot as plt
import numpy as np
fig = plt.figure()
ax = fig.add_axes([0.1,0.1,0.8,0.8], polar=True)
# ax.invert_yaxis()
ax.set_theta_zero_location('N')
ax.set_rlim(90, -45, 1)
# Note: you must set the end of arange to be slightly larger than 90 or it won't include 90
ax.set_yticks(np.arange(-45, 91, 15))
ax.set_yticklabels(ax.get_yticks()[::-1])
ax.plot([0,10,20], 90-np.array([12,13,14]), linestyle='', marker='.')
fig.show()
Problem
I'm trying to create an astronomical polar plot with a radial axis that starts from -45° on outer line and increases to 90° in the center of the plot. But I didn't find any way to reverse radial axis of the PolarAxes instance. `invert_yaxis()` method doesn't work at all. Also, there are some hidden methods such as `ax.set_rlim()` that doesn't have any docs. Here is my current code: ``` fig = plt.figure() ax = fig.add_axes([0.1,0.1,0.8,0.8], polar=True) # ax.invert_yaxis() ax.set_theta_zero_location('N') ax.set_ylim(-45, 90) ax.set_yticks(np.arange(-45, 90, 15)) ax.plot(ras, decs, linestyle='', marker='.') ``` and my plot