Statistical estimators used in regression or optimization problems. Implemented metrics:

• RSS (Residual Sum of Squares):

• MSE (Mean Squared Error):

• MSPE (Mean Squared Percentage Error):

• RMSE (Root-Mean-Square Error):

• RMSPE (Root-Mean-Square Percentage Error):

• MAE (Mean Absolute Error):

• MAPE (Mean Absolute Percentage Error):

• RSE (Relative Squared Error):

• RAE (Relative Absolute Error):

• R2 (Coefficient of determination):

Where is the actual value, is the forecasted value, and are the average of the variable and the number of samples, respectively.