Hi!
I was having difficulty inputting bounds for the aperiodic fitting. When I would initialize self._ap_bounds with values other than np.inf I would get an error when the spec param _simple_ap_fit function called curve_fit. Inside curve_fit and subsequently least_squares this seems to cause some change in the guess parameters which leads to a ValueError resulting from the guess variable having the wrong dimensions. I think this dimension check only happens when you input restricted bounds. I can get rid of the error by indexing the guess variable that gets passed into curve_fit:
In _simple_ap_fit I add “[0]”:
guess = np.array([off_guess + kne_guess + exp_guess])[0]