James, I see that you have implemented a strategy change in axes.py for inverted axes, with corresponding additions to the API. I don't have strong opinions about the strategy. Keeping track of orientation via a flag is reasonable, although I'm not positive it is better, given that it complicates the API. My first reaction to the new API is at best lukewarm, however, so perhaps it is worth a bit of thrashing out on the list. What you have now (and similarly for yaxis): + def invert_xaxis(self, invert=True): + "Invert the x-axis if 'invert' is True." + self._invertedx = invert + + def xaxis_inverted(self): + 'Returns True if the x-axis is inverted.' + return self._invertedx Some alternatives: 1) Attributes (could later be properties or those terrifying traits): x_right=True or False y_up xdir 'right' or 'normal' or True; vs 'left' or 'reversed' or False and similarly for ydir 2) Getters and setters: set_xdir() with values as some selection from above ydir() similar set_xRight(False) yUp(False) Matlab uses "xdir", "reversed" etc. I like the idea of being more descriptive, with "right"|"left" and "up"|"down", either as values or in the function and/or attribute names. I also thought the old scheme of xlim(5,0) was elegant; the problem was that there and in related functions the variables should have been called "left" and "right", not "xmin" and "xmax". I could probably come up with more possibilities, but first I want to see whether anyone agrees that this might be a good time to think about API strategy and consistency. Eric