% This function accepts binding data (Y) and returns a vector, Yhat, of fitted
% binding values corresponding to the original ligand concentration data.
% It also returns the fitting parameters KD and n.
% The model Y = L^n/(L^n + KD^n) is used for this fit, which assumes ligand is in excess.

  function Yhat = Fit_KDn(C, x)

     KD = C(1);
     n = C(2);   

     Yhat = (x.^n)./(x.^n + KD.^n);