"""
==================
Parasite Axes demo
==================

Create a parasite axes. Such axes would share the x scale with a host axes,
but show a different scale in y direction.

This approach uses `mpl_toolkits.axes_grid1.parasite_axes.HostAxes` and
`mpl_toolkits.axes_grid1.parasite_axes.ParasiteAxes`.

An alternative approach using standard Matplotlib subplots is shown in the
:doc:`/gallery/ticks_and_spines/multiple_yaxis_with_spines` example.

An alternative approach using :mod:`mpl_toolkits.axes_grid1`
and :mod:`mpl_toolkits.axisartist` is found in the
:doc:`/gallery/axisartist/demo_parasite_axes2` example.
"""

from mpl_toolkits.axisartist.parasite_axes import HostAxes, ParasiteAxes
import matplotlib.pyplot as plt


fig = plt.figure()

host = HostAxes(fig, [0.15, 0.1, 0.65, 0.8])
par1 = ParasiteAxes(host, sharex=host)
par2 = ParasiteAxes(host, sharex=host)
host.parasites.append(par1)
host.parasites.append(par2)

host.set_ylabel("Density")
host.set_xlabel("Distance")

host.axis["right"].set_visible(False)
par1.axis["right"].set_visible(True)
par1.set_ylabel("Temperature")

par1.axis["right"].major_ticklabels.set_visible(True)
par1.axis["right"].label.set_visible(True)

par2.set_ylabel("Velocity")
offset = (60, 0)
new_axisline = par2.get_grid_helper().new_fixed_axis
par2.axis["right2"] = new_axisline(loc="right", axes=par2, offset=offset)

fig.add_axes(host)

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

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

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["right2"].label.set_color(p3.get_color())

plt.show()
