Nice looking Percents on Mouse-Over Chart Interactivity in Birt

If you're incorporating a mouse-over interactive feature in a Birt Chart and your data point is a percent, the resulting data flash can look sort of ugly (like 0.021200). You can control this by editing the format of the tooltip text.

a = row["PERCENT_CLOSED"]
a = a.toPrecision(2)*100
a = a+'%'

This should result in the percentage being displayed at as 21% as opposed to 0.021200. Occasionally I get some strange results like 21.0000004% that I can't really explain.