COMPARISON OF LS TECHNIQUES FOR THE LINEAR APPROXIMATION OF DATA AFFECTED BY HETEROSCHEDASTIC ERRORS IN BOTH VARIABLES WITH UNCERTAINTY ESTIMATION

Various least squares methods have been compared in respect to the straight line fitting to data sets with errors on both variables, to check the benefit in using the most appropriate method for dealing with heteroschedastic data, the element-wise total least squares (EW TLS). It is found that the EW TLS always gives the correct estimate: weighted least squares can sometimes be also a good approximation, but this cannot be guessed a priori.