Hi @michaelh,
I see just what you're experiencing -- setting the axis with an Increment=0.2, and Minor Ticks=0 returns this graph for me as well:
Which, as you observed, isn't an increment of 0.2, but rather of 1. I think what's happening is the JMP axis display logic, to not have labels that overlap, is clashing with your specification. We can get around this by specifying an increment that JMP can display with the labels, such as an increment of 2, but then have the number of minor ticks specified to make intervals of 0.2 -- so, that's 9 minor ticks (at 0.2,0.4,0.6,0.8,1.0,1.2,1.4,1.6,1.8). Doing that returns:
Does that work for you as a solution?
I don't recommend it, but one alternative to not have the axis display logic clash with the increment is to make the graph as big as possible, and decrease your font size until it's possible to display the labels for your increment. If you do that, nothing clashes and jmp will go ahead with an increment = 0.2 and no minor ticks.
One final option, which I suggest only if you have every increment represented in the data, is to make the X axis column Nominal. That will force the display of each measured bin, with jmp packing the (now categorical) labeling the best it can:
@julian