旋转Matplotlib寄生图中的x轴标签

Question

After Thomas very helpfully fixed my issues making two parasite sub plots in this question , I'm now trying to rotate the x axis labels on the subplots.

Unfortunately, my modification to the example code here seems to have no effect on the x axis labels:

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import host_subplot
import mpl_toolkits.axisartist as AA

host = host_subplot(111, axes_class=AA.Axes)
plt.subplots_adjust(right=0.75)

par1 = host.twinx()
par2 = host.twinx()

offset = 60
new_fixed_axis = par2.get_grid_helper().new_fixed_axis
par2.axis["right"] = new_fixed_axis(loc="right",
                                    axes=par2,
                                    offset=(offset, 0))

par1.axis["right"].toggle(all=True)
par2.axis["right"].toggle(all=True)

host.set_xlim(0, 2)
host.set_ylim(0, 2)

host.set_xlabel("Distance")
host.set_ylabel("Density")
par1.set_ylabel("Temperature")
par2.set_ylabel("Velocity")

p1, = host.plot([0, 1, 2], [0, 1, 2], label="Density")
p2, = par1.plot([0, 1, 2], [0, 3, 2], label="Temperature")
p3, = par2.plot([0, 1, 2], [50, 30, 15], label="Velocity")

par1.set_ylim(0, 4)
par2.set_ylim(1, 65)

host.legend()

host.axis["left"].label.set_color(p1.get_color())
par1.axis["right"].label.set_color(p2.get_color())
par2.axis["right"].label.set_color(p3.get_color())

plt.xticks(rotation = 45) #<- The only change from the example

plt.draw()
plt.show()  

gives un-rotated x axis labels in:

Although I've shown the plt.xticks(rotation = 45) , I've also tried other ways that work with "conventional" matplotlib plots without success. Does anyone know if there is a way to do this, or am I just dealing with too much of a niche case? Maybe I should just figure out a way to live with using sub plots and no parasite axes?

Thanks a lot, Alex

Answer 1

There are two ways to produce parasite axes:

• Using the mpl_toolkits axisartist and axes_grid1 package, examples are

  • demo_parasite_axes
  • demo_parasite_axes2
  • this stackoverflow answer

• Using usual subplots and their spines. Examples are

  • multiple_yaxis_with_spines
  • this stackoverflow answer

Here you are using the first approach, which may be a bit unintuitive due to it using the special axes provided by the axisartist toolkit.

Solution 1:

Use the usual subplots approach for which all the usual ways of rotating ticklabels work just fine, eg

plt.setp(ax.get_xticklabels(), rotation=90)

Solution 2:

In case you want to stick with the mpl_toolkits approach you need to obtain the ticklabels from the axis via axis["right"].major_ticklabels ,

plt.setp(par2.axis["bottom"].major_ticklabels, rotation=-135)