I've been rewriting the Arrow class in patches.py to improve the look of quiver plots and am getting generally good results. The problems with current quiver plots are that arrows representing very small values are scaled along their length but not in width and also that arrowheads are not of a constant size. I have addressed both of these problems and getting results much more like Matlab quiver plots now. However, now that I am scaling arrow patches down to very small sizes, I see weird shaped arrows at some zoom levels but when I zoom in close enough to see the shape properly they look nicely formed. Is there a known problem, perhaps with Agg doing some fancy truncation in order to achieve good speed, where patches are distorted if their vertices are very close together at a particular magnification? I can provide code and graphic examples if it would help.