Demo Parasite Axes2

Parasite axis demo

The following code is an example of a parasite axis. It aims to show how to plot multiple different values onto one single plot. Notice how in this example, par1 and par2 are both calling twinx meaning both are tied directly to the x-axis. From there, each of those two axis can behave separately from the each other, meaning they can take on separate values from themselves as well as the x-axis.

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 Demo Parasite Axes 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
import mpl_toolkits.axisartist as AA
import matplotlib.pyplot as plt

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.show()