Consider a Column chart and I want to draw a circle for [Europe, 0]. Works as expected - http://jsfiddle.net/a5h870wt/2/
But for a Bar chart, the circle is not at the correct place: http://jsfiddle.net/a5h870wt/3/
The solution is to swap the computed x and y if they were calculated from xValue and yValue after this line: https://github.com/blacklabel/annotations/blob/master/js/annotations.js#L602
Here's how it looks: http://jsfiddle.net/a5h870wt/4/
I have a commit here with the fix: eltonjude@d453f71
If you could suggest other properties that would have similar issue, I can include fixes for them in a PR with the above fix.
Thanks