How to share axes after adding subplots via add_subplot?

Question

I have a dataframe like this:

df = pd.DataFrame({'A': [0.3, 0.2, 0.5, 0.2], 'B': [0.1, 0.0, 0.3, 0.1], 'C': [0.2, 0.5, 0.0, 0.7], 'D': [0.6, 0.3, 0.4, 0.6]}, index=list('abcd'))     

    A    B    C    D
a  0.3  0.1  0.2  0.6
b  0.2  0.0  0.5  0.3
c  0.5  0.3  0.0  0.4
d  0.2  0.1  0.7  0.6

Now I want to plot each row as a barplot whereby the y-axis and the x-tick-labels are shared using add_subplot.

Until now, I can only produce a plot that looks like this:

There is one problem:

The axes are not shared, how one do this after using add_subplot? Here, this problem is solved by creating one huge subplot; is there any way to do this in a different manner?

My desired outcome looks like the plot above with the only difference, that there are no x-tick-labels in the upper row and now y-tick-labels in the right column.

My current attempt is the following:

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np

df = pd.DataFrame({'A': [0.3, 0.2, 0.5, 0.2], 'B': [0.1, 0.0, 0.3, 0.1], 'C': [0.2, 0.5, 0.0, 0.7], 'D': [0.6, 0.3, 0.4, 0.6]}, index=list('abcd'))

fig = plt.figure()
bar_width = 0.35
counter = 1
index = np.arange(df.shape[0])

for indi, rowi in df.iterrows():

    ax = fig.add_subplot(2, 2, counter)
    ax.bar(index, rowi.values, width=bar_width, tick_label=df.columns)
    ax.set_ylim([0., 1.])
    ax.set_title(indi, fontsize=20)
    ax.set_xticks(index + bar_width / 2)
    counter += 1

plt.xticks(index + bar_width / 2, df.columns)

Do you mean *shared* as in `add_subplot(..., sharex=, sharey=)`? — MB-F, Feb 21 '17 at 15:09
@kazemakase: If these flags, `sharex=`, `sharey=`, existed in `add_subplot`, that would indeed be perfect. But I don't see such flags. — Cleb, Feb 21 '17 at 15:11
Have you tried? Or are you just saying that they don't exist because you are too lazy? — ImportanceOfBeingErnest, Feb 21 '17 at 15:16
@Cleb You are right, I can't find this in the documentation either. Still, it works - at least on my machine with Matplotlib 1.5.2. — MB-F, Feb 21 '17 at 15:19
@ImportanceOfBeingErnest `fig.add_subplot?` returns as potential flags (only the ones starting with s): `sketch_params: unknown snap: unknown` So no, I did not try whether `sharex`, `sharey` exist as they are not listed... — Cleb, Feb 21 '17 at 15:21
See: http://matplotlib.org/users/recipes.html#easily-creating-subplots — Nickil Maveli, Feb 21 '17 at 15:23
In the documentation of [add_subplot(*args, **kwargs)](http://matplotlib.org/api/figure_api.html#matplotlib.figure.Figure.add_subplot) it says *kwargs are legal Axes kwargs plus projection* and [`Axes`](http://matplotlib.org/api/axes_api.html#axes-class) does have `sharex=None, sharey=None` as arguments. — ImportanceOfBeingErnest, Feb 21 '17 at 15:23
https://stackoverflow.com/questions/42973223/how-to-share-x-axes-of-two-subplots-after-they-have-been-created — Martijn Courteaux, Apr 17 '23 at 09:18

score 2 · Accepted Answer · edited May 23 '17 at 12:16

The question how to produce shared subplots in matplotlib:

The SO seach engine results
The matplotlib recipes or the examples page

What may be more interesting here, is that you could also directly use pandas to create the plot in a single line:

import pandas as pd
import matplotlib.pyplot as plt

df = pd.DataFrame({'A': [0.3, 0.2, 0.5, 0.2], 'B': [0.1, 0.0, 0.3, 0.1], 'C': [0.2, 0.5, 0.0, 0.7], 'D': [0.6, 0.3, 0.4, 0.6]}, index=list('abcd'))
df.plot(kind="bar", subplots=True, layout=(2,2), sharey=True, sharex=True)
plt.show()

How to share axes after adding subplots via add_subplot?

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