使用 AxesGrid 时出现意外结果

Question

This code

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import AxesGrid

mat0 = [[1, 2], [3, 4], [5, 6], [7, 8]] # 4 rows × 2 columns
mat1 = [[-2, 0, 2, 4], [0, 2, 4, 6]]    # 2 rows × 4 columns

fig = plt.figure(figsize=(9, 3))
grid = AxesGrid(fig, 111, nrows_ncols=(1,2),
                axes_pad=0.15,
                cbar_size="6%", cbar_location="right", cbar_mode="single")
for ax, mat in zip(grid.axes_all, (mat0, mat1)): im = ax.imshow(mat)
grid.cbar_axes[0].colorbar(im)

plt.figure()
plt.imshow(mat0)
plt.colorbar()

plt.show()

produces two Figures

I expected to see, in the first one, a tall rectangle in the left, as in the second Figure.

Of course I'm not understanding what is really happening with AxesGrid.

How can I have the two Images side by side, without the tall one being truncated?

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Is an image worth 1000 words?

Answer 1

If you're dealing with images of different dimensions, it can be tricky to display them side by side with equal height while maintaining their aspect ratio. A simpler alternative, and for me a more elegant solution, might be to just use subplots and share the colorbar. Here's how you can do it:

import matplotlib.pyplot as plt
import numpy as np

mat0 = np.array([[1, 2], [3, 4], [5, 6], [7, 8]]) # 4 rows × 2 columns
mat1 = np.array([[-2, 0, 2, 4], [0, 2, 4, 6]])    # 2 rows × 4 columns

fig, axs = plt.subplots(1, 2, figsize=(9, 3))

cax = axs[0].imshow(mat0)
axs[1].imshow(mat1)

fig.colorbar(cax, ax=axs.ravel().tolist(), shrink=0.5)

plt.show()

In this script, subplots creates a 1x2 grid of axes. The images are displayed on these axes using imshow . The colorbar is shared across the subplots with the help of fig.colorbar . The shrink parameter adjusts the size of the colorbar. You may need to adjust the figsize parameter to better suit your data and display size.

This is the result:

I hope this helps.