Parasite axis demo

This example demonstrates the use of parasite axis to plot multiple datasets onto one single plot.

Notice how in this example, par1 and par2 are both obtained by calling twinx(), which ties their x-limits with the host's x-axis. From there, each of those two axis behave separately from each other: different datasets can be plotted, and the y-limits are adjusted separately.

Note that this approach uses the mpl_toolkits.axes_grid1.parasite_axes' host_subplot and mpl_toolkits.axisartist.axislines.Axes. An alternative approach using the parasite_axes's HostAxes and ParasiteAxes is the Parasite Axes demo example. An alternative approach using the usual Matplotlib subplots is shown in the Multiple Yaxis With Spines example.

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

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

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

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

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

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")

host.set_xlim(0, 2)
host.set_ylim(0, 2)
par1.set_ylim(0, 4)
par2.set_ylim(1, 65)

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

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.show()