Matplotlib 颜色栏不显示 2 个离散值的标签

Question

With an array of 3 discrete values I can use imshow to create a colorbar.

import numpy as np
from matplotlib import pyplot as plt

img_data1 = np.random.choice([0,1,2], size=100).reshape((10,10))

plt.imshow(img_data1)
plt.colorbar(ticks = [0,1,2], values = [0,1,2])

Produces:

But if the array only has 2 discrete values, [0,1] , the colorbar labels are missing.

img_data2 = np.random.choice([0,1], size=100).reshape((10,10))

plt.imshow(img_data2)
plt.colorbar(ticks = [0,1], values = [0,1])

Produces:

How can I make the the color bar with 2 values have ticks marks and labels?

Answer 1

Your code work fine for me:

I am using matplotlib 3.4.2. Try to update your package if it is not up to date.

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In any case, you can customize colorbar labels with:

cbar = plt.colorbar(ticks = [0,1], values = [0,1])
cbar.ax.get_yaxis().set_ticks([0, 0.25, 0.5, 0.75, 1]) # pass the array of labels you want