I envision the array on a continuous axis, and place markers at 1 and 3 (the exact positions, not the range of whole numbers). The range on the axis between them is the right range. With this intuition, everything is very simple and makes perfect sense.
Yes, it makes perfect sense, but it still feels wrong for me. I guess it is just related to the fact that I grew up with Matlab and not Python. I was kind of hoping I will get used to it but even after several years of writing image processing stuff in Python I am still not a 100% convinced.
