Does anyone know how it we can robustly standardize the residuals in MM regression?
I mean that first we perform MM regression and then obtain the residuals. how we can robustly standardized the residuals obtain from MM regression? I have found the method for least median squares(LMS) and least trimmed mean square (LTS) which the scale of the errors is estimated using a formula and then the residuals will be divided to that estimated scale. But for MM regression I couldnt find a formula for estimating the scale of the errors in order to standardize the residuals.

Thanks for your help,