Matplotlib savefig with tight layout and suptitle generates extra space between title and images

Question

On the web, I have found similar issues but I have not figured out the solution yet.

The following code:

import numpy as np
import matplotlib.pyplot as plt

imgs = [np.random.randint(0, 256, size=(512, 512, 3)) for _ in range(3)]

_, axes = plt.subplots(1, 3)
title = plt.suptitle("My title")
axes[0].imshow(imgs[0])
axes[0].set_axis_off()
axes[1].imshow(imgs[1])
axes[1].set_axis_off()
axes[2].imshow(imgs[2])
axes[2].set_axis_off()
plt.savefig("myfig.png", bbox_inches="tight",
            bbox_extra_artists=[title])
plt.close()

Gives me the following output:

How can I remove the extra space between the title and the images?

Answer 1

The problem here is that your axes have a fixed aspect ratio, and your plot is taller than needed. There will be white space above and below your plot, which you try and get rid of with box_inches='tight'.

A straightforward solution in Matplotlib is to make the aspect ratio of the figure close to the aspect ratio of the axes:

fig, axs = plt.subplots(1, 3, figsize(6, 2)

is close, and then you can play with the result after.

A second approach is to not use suptitle, which is generic, and instead use ax.text directly, and use the transAxes property of the axes to make the x and y be in fraction of the axes:

axes[1].text(0.5, 1.02, 'Boo!!!!!!', transform=axes[1].transAxes, ha='center')