Unable to create a tight and neat plot with ImageGrid

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This is going to be a somewhat long post, so please bear with me.

I’m used to be able to either use tight_layout or constrained_layout to produce plots that are nice and tight, but there seems to be a lack of support for both tight_layout and constrained_layout when it comes to ImageGrid plots. Below is an example where I plot a 5 x 2 grid with ImageGrid and use constrained_layout=True:

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import ImageGrid

# Data to populate plots.
im = np.arange(100).reshape((10, 10))

fig = plt.figure(figsize=(3, 6), constrained_layout=True)
grid = ImageGrid(fig, 111,
                 nrows_ncols=(5, 2),
                 axes_pad=0.2,
                 label_mode="L")

for ax in grid:
    ax.imshow(im)

fig.suptitle("Testing a suptitle on with ImageGrid")
fig.savefig("imagegrid_suptitle.png")

This results in the following warning: UserWarning: There are no gridspecs with layoutgrids. Possibly did not call parent GridSpec with the "figure" keyword. The plot that is produced has a lot of dead-space on the top, sides, and bottom:

imagegrid_suptitle
imagegrid_suptitle300×600 11.2 KB

Compare this to the plot of a subplots figure that also uses constrained_layout:

import numpy as np
import matplotlib.pyplot as plt

# Data to populate plots.
im = np.arange(100).reshape((10, 10))

fig, axs = plt.subplots(5, 2, figsize=(3, 6), sharex=True, sharey=True, constrained_layout=True)

for ax in axs.flat:
    ax.imshow(im)

fig.suptitle("Testing a suptitle with subplots")
fig.savefig("subplots_suptitle.png")

You’ll have to take a look at the second plot here since I’m only allowed to upload one embedded image as a new user: https://imgur.com/a/fGS1WiT

In the subplots figure there’s a minimum of dead-space, and the suptitle is very close to the top of the two upmost subplots.

Using tight_layout instead gives bad results with both ImageGrid and subplots, and the following warning is produced by the ImageGrid plot: UserWarning: This figure includes Axes that are not compatible with tight_layout, so results might be incorrect. Check the third and fourth plots here: https://imgur.com/a/fGS1WiT

So, is there something I’m missing, or doesn’t constrained_layout support ImageGrid? If that’s the case how can I get rid of the dead-space?