CODEWITHSUNDEEP
pythonmatplotlibcolorbar
Wolfmercury
Wolfmercury

Reputation: 124

Change Colorbar limit for changing scale with matplotlib 3.3+

The code at the bottom does exactly what I want it to do, but exclusively to a matplotlib version below at least 3.3.4 . For this version, 3.3.4, I get the following error message:

AttributeError: 'ColorBar' object has no attribute 'set_clim'

Accordingly, I tried to find out, how to do this in today's version, but failed. So, how can I change the color scale of the image and the Colobar in the newer versions?

Working Code (tested in 2.2.2):

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

x = np.linspace(0, 10, 100)
y = np.cos(x)
y = y.reshape(10,10)

plt.ion()

figure = plt.figure()
line1 = plt.imshow(y)
cbar = plt.colorbar(line1)

for p in range(100):
    updated_y = np.random.randint(0,10)*np.cos(x-0.05*p).reshape(10,10)
    
    line1.set_data(updated_y)

    cbar.set_clim(vmin=np.min(updated_y),vmax=np.max(updated_y)) #this line creates the error
    cbar.draw_all()
    
    figure.canvas.draw()
    figure.canvas.flush_events()
    time.sleep(1)

Upvotes: 3

Views: 6920

Answers (2)

Trenton McKinney
Trenton McKinney

Reputation: 62373

import matplotlib.image as mpimg
import matplotlib.pyplot as plt

img = mpimg.imread('stinkbug.png')
lum_img = img[:, :, 0]

fig, (ax1, ax2)= plt.subplots(1, 2, figsize=(10, 7))

im1 = ax1.imshow(lum_img)
im1.set_cmap('nipy_spectral')
ax1.set_title('Before')
fig.colorbar(im1, ax=ax1, ticks=[0.1, 0.3, 0.5, 0.7], orientation='horizontal')

im2 = ax2.imshow(lum_img)
im2.set_cmap('nipy_spectral')
im2.set_clim(0.0, 0.7)  # set clim on the im2 image object
ax2.set_title('After')
fig.colorbar(im2, ax=ax2, ticks=[0.1, 0.3, 0.5, 0.7], orientation='horizontal')

enter image description here

Upvotes: 4

Wolfmercury
Wolfmercury

Reputation: 124

I found a solution with the by @Trenton McKinneys provided link in the following post: Question by Merk.

Solved code:

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

x = np.linspace(0, 10, 100)
y = np.cos(x)
y = y.reshape(10,10)

plt.ion()

figure = plt.figure()
line1 = plt.imshow(y)
cbar = plt.colorbar(line1)

for p in range(100):
    updated_y = np.random.randint(0,10)*np.cos(x-0.05*p).reshape(10,10)
    
    line1.set_data(updated_y)

    #cbar.set_clim(vmin=np.min(updated_y),vmax=np.max(updated_y)) #this line creates the error
    cbar.mappable.set_clim(vmin=np.min(updated_y),vmax=np.max(updated_y)) #this works
    cbar.draw_all()
    
    figure.canvas.draw()
    figure.canvas.flush_events()
    time.sleep(1)

(One) provided image: enter image description here

Upvotes: 5

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