Cycling example: valueAxis bug

The value given changes unreasonably based on zoom level.

I zoomed in fully and positioned the cursor at 2:43:47

The reading for speed was 15 which is approximately correct from what is plotted. I slowly zoomed out being careful not to move the cursor, and got the following series of speed values in the order shown:

15 (fully zoomed in)
22
25
24
23
28
27
16 (fully zoomed out)

I repeated the same process and got slightly different values but the same general trend (small and high zoom, large at medium zoom, small at small zoom).