No, I don't think the issue is a flip in the y-axis. I have a number of different examples of this, and many in which the contour is an ellipse so I can tell that the overall positioning is correct. It seems like something is going wrong only when I save the image... Thanks for the suggestion though!
On Wed, Jul 21, 2010 at 3:40 PM, Jenna Lemonias <email@example.com>wrote: > I am trying to save a matplotlib 2d array image with an overlaid contour as > an eps file. The contour appears to be shifted with respect to the image > underneath in the eps file, particularly when I zoom in on the image. This > shift is not noticeable in the plot within matplotlib. > > I am using imshow to display the image. The contour is created by plotting > a list of closely-spaced x,y coordinates. The attached file matplotlib.png > is a screenshot of the (zoomed-in) image as displayed by matplotlib. The > attached file epsfile.png is a screenshot of the (zoomed-in) eps file. When > I save this image as an eps file, it is actually 1 of 20 subplots and the > shift is noticeable in each subplot. > > Thanks in advance for your help! > > Jenna > > Just as a wild guess, could this actually be an issue with how imshow uses the upper-left corner for (0,0)? I have seen 1-pixel shifts before, but this shift is a little dramatic and I am left wondering if what we are really seeing is that the contour that is desired should actually be fliped in the y-axis? Maybe you could try another example where you try to draw a contour further away from the center of the image and see if it still goes in the spot you expect it to be? Ben Root