Are you using the latest 1.0.0b1 build (available from bitbucket
downloads:
https://bitbucket.org/cleonello/jqplot/downloads)? You
should get much better, "round number" ticks with that build. To get
the "rounder" ticks, you must NOT specify an axis min, max,
numberTicks or tickInterval. Let the plot figure everything out.
The format string, will just format the display of the tick value on
the plot. So, a tick value of 2.2 with %d format will show up as 2,
but the actual value will still be 2.2.
While this is what a format string is supposed to do, the desired
behavior by many users is for the format string to affect the actual
value of the tick. This causes confusion.