多个图的相同 bbox 大小

Question

I have the issue that I am trying to make multiple plots that are supposed to have the same bbox size. As some of my plots have an additional colorbar or wider yticklabels the bbox size varies within multiple plots.

As I would like to use these plots in a LaTex document underneath each other, I would like to set the bbox for all plots to the same value instead of defining the figure size.

If it is not clear yet what I mean, here's an example:

As you can see the bbox sizes vary, as the width of the ylabel + ylabelticks and additionally the cbar is added. I thought the easisest way to approach this would be to find the image of the smallest drawn bbox and use that as a standard for all figures and keep the figsize constant, or to just set the bbox size constant and just add the rest and have varying figsizes.. the later would need me to do additional positioning in latex/illustrator/power point or whatever, but just about any solution that works would be great (even though I belive that the later is likely not possible with matplotlib). I tried changing the bbox size but unfortunately did not succeed. So I do not have some code to start from. But any help or pointers where to look at or start would help a lot.

Here a short code snippet to reproduce.

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt

np.random.seed(1)
mpl.rcParams['figure.figsize'] = (16.0, 12.0)
x = np.linspace(0, 100, 100)
y = np.random.randint(100, size=100)
z = np.random.randint(0, 1e6, size=100)/1e6


fig, ax = plt.subplots()
m = mpl.cm.ScalarMappable(cmap=mpl.cm.jet)
norm = plt.Normalize(min(z), max(z))
m.set_array(list(set(z)))
cbar = plt.colorbar(m, orientation="vertical", fraction=0.07, pad=0.02)
color = lambda c: m.cmap(norm(c))
ax.scatter(x, y, color=color(z))


fig, ax = plt.subplots()
ax.scatter(x, y)

Answer 1

pls see following code. I recommend you using ax1 and ax2 , which have more flexibility.

Key points:

• using get_position() to get bounds of axes.
• using set_position() to set bounds of axes.

I highly recommend using ax1, ax2 ... instead of plt.stuff for multiple subplots.

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt

np.random.seed(1)
x = np.linspace(0, 100, 100)
y = np.random.randint(100, size=100)
z = np.random.randint(0, 1e6, size=100)/1e6


fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(8, 4))
m = mpl.cm.ScalarMappable(cmap=mpl.cm.jet)
norm = plt.Normalize(min(z), max(z))
m.set_array(list(set(z)))
cbar = fig.colorbar(m, orientation="vertical", fraction=0.07, pad=0.02)
color = lambda c: m.cmap(norm(c))
ax2.scatter(x, y, color=color(z))
ax1.scatter(x, y)

# get the bounds of ax1 and ax2
x1, y1, w1, h1 = ax1.get_position().bounds
x2, y2, w2, h2 = ax2.get_position().bounds
# set ax1 width to width of ax2
ax1.set_position([x1, y1, w2, h1])