I'm guessing it's a sine thing. Like a 90 degree AP would show up as 1, and 0 degrees would be 0, so 45 degrees would end up being 0.7071. RA2 only turns components in 10 degree increments anyway, so a 37 degree AP seems a little bit too awkward, in my view. Just stick to multiples of 5 for now, I reckon.