PWD_RL                  Weighted Deming - Rocke-Lorenzato - known
                        sigma, kappa
PWD_get_gh              Estimate of Variance Profile Functions
                        (proportional)
PWD_inference           Weighted Deming Regression - Inference
PWD_known               Weighted Deming Regression - general weights
PWD_outlier             Weighted Deming Regression - Outlier scanning
PWD_resi                Fit Rocke-Lorenzato profile model to residuals
WD_General              Weighted Deming Regression
WD_Linnet               Linnet proportional CV weighted Deming
