Refreshing an image from imshow after set_data()

Hello all,

I'm making a small visualization application based on matplotlib which is in turn embedded in gtk2 using pygtk. The code goes like this:

fig = matplotlib.figure()
ax = fig.add_subplot(111)
im = ax.imshow(A)
canvas = FigureCanvas(fig)
[...]

and it works fine. However, after an user action I need to update the image, and so I do a

im.set_data(NewData)

but the image remains unchanged, and will only update if I somehow move it using the toolbar. I googled a bit and found that perhaps fig.draw(renderer) would work, but I have no idea as how to get a reference to the renderer. Any ideas?

Thanks,
Jo´┐Żo Silva