Matplotlib: Adding an axes using the same arguments as a previous axes

Question

I want to plot data, in two different subplots. After plotting, I want to go back to the first subplot and plot an additional dataset in it. However, when I do so I get this

Answer 1

I had the same problem. I used to have the following code that raised the warning:

(note that the variable Image is simply my image saved as numpy array)

import numpy as np
import matplotlib.pyplot as plt

plt.figure(1)  # create new image
plt.title("My image")  # set title
# initialize empty subplot
AX = plt.subplot()  # THIS LINE RAISED THE WARNING
plt.imshow(Image, cmap='gist_gray')  # print image in grayscale
...  # then some other operations

and I solved it, modifying like this:

import numpy as np
import matplotlib.pyplot as plt

fig_1 = plt.figure(1)  # create new image and assign the variable "fig_1" to it
AX = fig_1.add_subplot(111)  # add subplot to "fig_1" and assign another name to it
AX.set_title("My image")  # set title
AX.imshow(Image, cmap='gist_gray')  # print image in grayscale
...  # then some other operations