In an experiment vector y is a measurement of vector x. I want to fit polynomial y=x to this data and find R^2. When I use polyfit(x,y,1), MATLAB gives me y=ax+b but I am interested in knowing the R^2 when the data is fitted to y=x. Could someone please help me on that?
I found cftool which can solve my problem. Could someone tell me how I can retrieve R^2 from the analysis of cftool when the data is fitted to a polynomial?