I was using LowerSum with 1 rectangle, and it did not show the correct rectangle (or compute the correct value). Same problem with UpperSum.
Please try 22.214.171.124:
(and please test with a few different cases, the problem wasn't just for 1 bar :) )
Thanks - this is a definite improvement. A bug still persists, but not as bad.
In the attached file, try zooming in on the top of the rectangle - you can see the height of the rectangle flickering between two values. Interestingly, the actual computed value for the height of the rectangle is constant (as seen in the algebra view). When you zoom way in, the picture is correct even though the value is wrong.
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