How to plot multiple numpy array in one figure?

Question

I know how to plot a single numpy array

import matplotlib.pyplot as plt
plt.imshow(np.array)

But is there any way to plot multiple numpy array in one figure? I know plt.subplots() can display multiple pictures. But it seems hard in my case. I have tried to use a for loop.

fig, ax = plt.subplots()
for i in range(10):
   ax.imshow(np.array)  # i_th numpy array

This seems to plot a single numpy array one by one. Is there any ways to plot all my 10 numpy arrays in one figure?

PS: Here each my 2d numpy array represents the pixel of a picture. plot seems to plot lines which is not suitable in my case.

Answer 1

The documentation for plt.subplots() (here) specifies that it takes an nrows and ncols arguments and returns a fig object and an array of ax objects. For your case this would look like this:

fig, axs = plt.subplots(3, 4)

axs now contains a 2D array filled with ax objects that you can use to plot various things, e.g. axs[0,1].plot([1,2],[3,4,]) would plot something on the first row, second column.

If you want to remove a particular ax object you can do that with .remove(), e.g. axs[0,1].remove().

For .imshow it works in exactly the same way as .plot: select the ax you want and call imshow on it.

A full example with simulated image data for your case would be:

import numpy as np
import matplotlib.pyplot as plt

fig, axs = plt.subplots(3, 4)
images = [np.array([[1,2],[3,4]]) for _ in range(10)]
for i, ax in enumerate(axs.flatten()):
    if i < len(images):
        ax.imshow(images[i])
    else:
        ax.remove()
plt.show()

With as the result: