Origin Version : 7 Operating System: Windows XP When doing non-linear fitting I don't see the curve change during the fitting process. If I click Done, then the fitted curve is displayed. Alternatively if I go to Simulate Curves page and click create curve, it creates the current curve but this doesn't change when I do a fit until I click this curve again. Is there a way to get the curve that is displayed to change as the paramaters are fitted? Chris
I have tried the Advance Fitting Tool in Origin 7, but I cannot reproduce the problem you have described. Would you please tell us more details on your operations? They might help us to figure out what happens.