I have a question about the attached MM notebook (just a few lines). I'm trying to fit a lineout through the digital image of a line pair gauge to a square wave. FindFit appears to fit the mean value (b) and at least takes a stab at fitting the amplitude (a); however, it seems to make no attempt to fit the offset on the x axis (x0). Why not? What am I missing?

Also, I would like to get more detail on the fit parameters, in particular, the uncertainties, but I haven't been able to figure out how to get MM to dump that information. How can I do that?

Thanks in advance for any help on this.