1

This is a follow-up to my previous question. The answer to that question showed the solution of using host_subplot a second time to produce the second graph, and is copied below for convenience.

I attempted to use this answer, but I got the error Unknown property gridspec_kw when trying to pass gridspec_kw to the host_subplot function.

How can I get differently sized subplots when one of the plots also has a double Y-axis using host_subplot?

"""
Parasite axis demo

The following code is an example of a parasite axis. It aims to show a user 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.
"""
from mpl_toolkits.axes_grid1 import host_subplot
import mpl_toolkits.axisartist as AA
import matplotlib.pyplot as plt

host = host_subplot(211, 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))

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())

## How can I make this subplot only 1/3 as tall as the first one?
host2 = host_subplot(212, axes_class=AA.Axes, sharex=host)
host2.plot([0,1,2], [5,6,7])
host2.set_title('Sharing X axis')

plt.draw()
plt.show()
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merlin2011
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2 Answers2

2

It appears that this can be done using the accepted answer to the linked question by replacing the first argument of host_subplot with a GridSpec. The added and changed lines are below.

from matplotlib import gridspec

# Two rows, one column, with height ratio of 4:1 between the top and bottom graph.
gs = gridspec.GridSpec(2, 1, height_ratios=[4, 1])

host = host_subplot(gs[0], axes_class=AA.Axes)
host2 = host_subplot(gs[1], axes_class=AA.Axes, sharex=host)
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merlin2011
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0

One way you could do this is by changing the number of rows in the two calls to host_subplot(). For a 3:1 height difference:

host = host_subplot(211, axes_class=AA.Axes)
host2 = host_subplot(614, axes_class=AA.Axes, sharex=host)

The first call divides the figure into 2 rows and selects the axis in the top half. The second call treats the figure as if it is divided into 6 rows and selects the subplot in the fourth row.

H/T: https://stackoverflow.com/a/3339129/7517724

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Craig
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