Automatic Fit Automatic Fit Performs an automatic chi-squared minimization for the particular set of data to the type of fit specified. Read more below for particulars concerning these fits.
Line Performs a fully automated least squares fit to the set of data.
Equation 6.12 on pg. If no X errors are being used, the calculations are performed only once and the parameters returned. MPL Fitting uses is no more than a brute force 'Grid-Search' method. It is described in Bevington and Robinson on pp. 141 to 153, with the uncertainties in the parameters calculated via equation 8.13 on pg.