MATLAB: Why the polynomial degree is less than 9 in the curve fitting tool

Question

i have 20 sets of (x,y) for polyfit,howerer,the degree is less than 9 in the cftool. such as the red circle in the figure why is 9 ? i want to see the results after 9…

Answer 1

It is rare that anything after degree 7 is meaningfully accurate if re-centering is off. It is rare that anything after degree 9 is meaningfully accurate if re-centering is on. Rare enough to make it not worth configuring.