径向 plot 的刻度放置，带有 r 的对数刻度

Question

I'm trying to create a radial plot with a logrithmic scale on the r-axis, but the tick labels for the theta are coming up inside the plot.

import numpy as np
from matplotlib import pyplot as plt

np.random.seed(1)
r = 10**(1 + 2*np.random.rand(36))
theta = 2 * np.pi * np.linspace(0, 1, 37)

fig, ax = plt.subplots(subplot_kw={'projection': 'polar'})
ax.plot(theta, r)
# We need to reset the minimum r-limit to avoid log(0)
ax.set_rlim(0.1, None)
ax.set_rscale('log')
plt.show()

The theta ticks are inside the figure, which doesn't look so bad here, but are hidden for eg a pcolormesh plot - for comparison, if I comment out the set_rlim and set_rscale lines, we get the following with the desired location for the ticks. (For anyone using dark mode, the image background is transparent so the ticks might not show inline.)

I've tried looking at the ax.get_xticklabels but the y-position (equivalently the r-position) is 0.

[Text(0.0, 0, '0°'),
 Text(0.7853981633974483, 0, '45°'),
 Text(1.5707963267948966, 0, '90°'),
 Text(2.356194490192345, 0, '135°'),
 Text(3.141592653589793, 0, '180°'),
 Text(3.9269908169872414, 0, '225°'),
 Text(4.71238898038469, 0, '270°'),
 Text(5.497787143782138, 0, '315°')]

Interestingly, if you increate the upper rlim (eg ax.set_rlim([0.1, 1e5]) ) the ticks move right to the edge of the figure.

Answer 1

You can use Axes.tick_params() to set the pad distance between the ticks and labels:

fig, ax = plt.subplots(subplot_kw={'projection': 'polar'})
ax.plot(theta, r)
ax.set_rmin(0.1)
ax.set_rscale('log')

ax.tick_params(pad=35)