Using matplotlib 0.87.2, I've been trying to plot points on top of an image. The image without points fills axes of the extent requested, but using plot to add a point on top of the image changes the axes lengths and gives unwanted white margins around the edges. Here's an example. Any help would be greatly appreciated!
from pylab import *
# Sample image.
image = rand(12,6)
# This choice for extent works fine... It produces no white margins.
#extent = [-80, 60, -60, 40]
# This choice gives unwanted white margins,
# except when no point is plotted.
extent = [-80.,64., -74.,48.]
ax1 = axes()
ax1.im = imshow(image, origin='lower', extent=extent)
# Plot point on image.