How can would I create 2 graphs on top of each other with both having the same x-axis and different y-axis?

Question

So say I have the data in the right format for a line graph on top of a colour map. How would I go about stacking them like seen below in Python with them both having the same x-axis but different y-axis?

Thanks

Answer 1

You can setup your axes like that using plt.subplots and the appropriate arguments (paying special attention to the gridspec_kw argument).

You want something like

gridspec_kw = dict(
    # Defines the heights of the two plots 
    # (bottom plot twice the size of the top plot)
    height_ratios=(1, 2),  
    # Zero space between axes
    hspace=0,
)

# Setup the figure with 2 rows, sharing the x-axis and with 
# the gridspec_kw arguments defined above
fig, axes = plt.subplots(
    nrows=2, ncols=1, sharex=True, 
    gridspec_kw=gridspec_kw,
)

Full example:

import numpy as np 
import matplotlib.pyplot as plt 

x = np.random.normal(size=10_000)
y = np.random.uniform(size=10_000)


gridspec_kw = dict(
    height_ratios=(1, 2),
    hspace=0,
)

fig, axes = plt.subplots(
    nrows=2, ncols=1, sharex=True, gridspec_kw=gridspec_kw,
)

axes[0].hist(x)
axes[1].hist2d(x, y)

plt.show()

will give you