If you are talking about the difference between your data and the fit curve, then you already have it. That's what Residuals are. Since the option to calculate residuals is on by default, you will find these values in the FitNLCurve worksheet.
In general you can subtract any plotted curves using Analysis : Mathematics : Simple Curve Math (also called Simple Math). Be sure to set your output to (<new>,<new>) unless it is your intent to change the original data.
(If you have some old version of Origin, you can click Residuals Plot in the Action : Results section of the fitter.) |