how do I redraw an image using python's matplotlib?

Question

What I am trying to do seems to be fairly straightforward, but I'm having a heck of a time trying to get it to work. I am simply trying to draw an image using imshow and then re-draw it periodically as new data arrives.

I've started out with this:

fig = figure()
ax = plt.axes(xlim=(0,200),ylim=(0,200))
myimg = ax.imshow(zeros((200,200),float))

Then I'm assuming I can call set_data like this to update the image:

myimg.set_data(newdata)

I've tried many other things, for example I've called ax.imshow(newdata) instead or I've tried using figure.show() after set_data().

Answer 1

You can simply call figure.canvas.draw() each time you append something new to the figure. This will refresh the plot.

from matplotlib import pyplot as plt
from builtins import input

fig = plt.figure()
ax = fig.gca()
fig.show()

block = False
for i in range(10):
    ax.plot(i, i, 'ko')
    fig.canvas.draw()
    if block: 
        input('pause : press any key ...')
    else:
        plt.pause(0.1)
plt.close(fig)