Hello, elie.maricau,
Personally is one of the details I like the most about JMP, the adaptive zooming axis.
In my experience you can fix the units, but not the "adaptive zoom". In a Column [Numeric, continuous], if you just do:
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And then select an increment for "Y" like:
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As soon as you move the axis the "Increment" adapts:
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It will show the same units, but t will adapt.
What I have done way to keep units fixed, is changing the Column type to "Numeric, Nominal". Then change the Format to something simple, like hours.
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This has worked for me. It keeps the ticks fixed.
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Hope it helps.
-Jose