How to properly label graphs that can be dimensionless?
One of reviewers of my document strongly emphasised on labelling plots with which I generally strongly agree. On this occasion, however, I was explaining a general mathematical model on generated time series and by time series I mean an observation (value of a variable) that changes. Non of the variables I'm plotting has any units and the only reason why I added label Time [s] on x axis so that reader doesn't have to think too much what is there. Reviewer suggested adding units to all other labels, such as dimensionless amplitude, amplitude square and inverse of amplitude square. It seems that adding
Density [1/|1|^2] or making up a unit might be considered a bit offensive.
Here are examples, where I am supposed to label axes. None of used variables requires a unit.