在子图中关闭轴

Question

I have the following code:

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

img = mpimg.imread("lena.jpg")

f, axarr = plt.subplots(2, 2)
axarr[0,0].imshow(img, cmap = cm.Greys_r)
axarr[0,0].set_title("Rank = 512")

rank = 128
new_img = prune_matrix(rank, img)
axarr[0,1].imshow(new_img, cmap = cm.Greys_r)
axarr[0,1].set_title("Rank = %s" %rank)

rank = 32
new_img = prune_matrix(rank, img)
axarr[1,0].imshow(new_img, cmap = cm.Greys_r)
axarr[1,0].set_title("Rank = %s" %rank)

rank = 16
new_img = prune_matrix(rank, img)
axarr[1,1].imshow(new_img, cmap = cm.Greys_r)
axarr[1,1].set_title("Rank = %s" %rank)

plt.show()

However, the result is pretty ugly because of the values on the axes:

How can I turn off axes values for all subplots simultaneously?

Answer 1

You can turn the axes off by following the advice in Veedrac's comment (linking to here ) with one small modification.

Rather than using plt.axis('off') you should use ax.axis('off') where ax is a matplotlib.axes object. To do this for your code you simple need to add axarr[0,0].axis('off') and so on for each of your subplots.

The code below shows the result (I've removed the prune_matrix part because I don't have access to that function, in the future please submit fully working code. )

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

img = mpimg.imread("stewie.jpg")

f, axarr = plt.subplots(2, 2)
axarr[0,0].imshow(img, cmap = cm.Greys_r)
axarr[0,0].set_title("Rank = 512")
axarr[0,0].axis('off')

axarr[0,1].imshow(img, cmap = cm.Greys_r)
axarr[0,1].set_title("Rank = %s" % 128)
axarr[0,1].axis('off')

axarr[1,0].imshow(img, cmap = cm.Greys_r)
axarr[1,0].set_title("Rank = %s" % 32)
axarr[1,0].axis('off')

axarr[1,1].imshow(img, cmap = cm.Greys_r)
axarr[1,1].set_title("Rank = %s" % 16)
axarr[1,1].axis('off')

plt.show()

Note: To turn off only the x or y axis you can use set_visible() eg:

axarr[0,0].xaxis.set_visible(False) # Hide only x axis

Answer 2

import matplotlib.pyplot as plt

fig, ax = plt.subplots(2, 2)

To turn off axes for all subplots, do either:

[axi.set_axis_off() for axi in ax.ravel()]

or

map(lambda axi: axi.set_axis_off(), ax.ravel())