set_markersize not working for right side axis

Question

I'm messing around with some plot styles and ran into a curiosity. I have a plot with twinx() to produce ticks on the right-hand side as well as the left. I want to stagger some ticks, some going farther out that others.

I can add padding to any tick on any axes and push out the text via ax.yaxis.get_major_ticks()[1].set_pad(), but when I try to lengthen the tick via ax.yaxis.get_major_ticks()[1].tick1line.set_markersize(), it works for all axes EXCEPT the right side. Any insight?

Please see the code below. I've tried switching up the axis (ax1, ax2) and index.

import matplotlib.pyplot as plt
import matplotlib as mpl
import numpy as np

t = np.linspace(0,5)
x = np.exp(-t)*np.sin(2*t)

fig, ax1 = plt.subplots()

ax1.plot(t, x, alpha=0.0)
ax2 = ax1.twinx()
ax2.plot(t, x, alpha=1.0)

ax1.set_xticks([0,1,2])
ax1.set_yticks([0.1, 0.2])
ax2.set_yticks([0.3, 0.4, 0.5])
ax2.set_xticks([1,2,3])

ax1.grid(True, color='lightgray')
ax2.grid(True, color='lightgray')

for a in [ax1, ax2]:
    a.spines["top"].set_visible(False)
    a.spines["right"].set_visible(False)
    a.spines["left"].set_visible(False)
    a.spines["bottom"].set_visible(False)

ax1.set_axisbelow(True)
ax2.set_axisbelow(True)

ax1.xaxis.get_major_ticks()[1].set_pad(15)  #
ax1.xaxis.get_major_ticks()[1].tick1line.set_markersize(15)

ax1.yaxis.get_major_ticks()[1].set_pad(15)  #
ax1.yaxis.get_major_ticks()[1].tick1line.set_markersize(15)

ax2.yaxis.get_major_ticks()[1].set_pad(15)  #
ax2.yaxis.get_major_ticks()[1].tick1line.set_markersize(15)

plt.savefig('fig.pdf')
plt.show()

Dementia

Answer 1

You need to use tick2line instead of tick1line, since that's the one referring to the top/right axis, according to the documentation.

Change ax2.yaxis.get_major_ticks()[1].tick1line.set_markersize(15) for:

ax2.yaxis.get_major_ticks()[1].tick2line.set_markersize(15)

Result:

Minotaur