Error

Formulation

MAE

$\frac{{\displaystyle {\sum }_{i=1}^n\left|y_i-x_i\right|}}{n}$

Kappa

$\frac{2\ast \left(\left(TP\ast TN\right)-\left(FN\ast FP\right)\right)}{\left(TP+FP\right)\ast \left(FP+TN\right)+\left(TP+FN\right)\ast \left(FN+TN\right)}$

RMSE

$\sqrt{\frac{1}{n}{\displaystyle {\sum }_{i=1}^n{\left(x_i-y_i\right)}^2}}$

RAE

$\frac{{\left[{\displaystyle {\sum }_{i=1}^n{\left(y_i-x_i\right)}^2}\right]}^{1/2}}{{\left[{\displaystyle {\sum }_{i=1}^n{x}_i^2}\right]}^{1/2}}$

RRSE

$\sqrt{\frac{{\displaystyle {\sum }_{j=1}^n{\left(y_{ij}-T_j\right)}^2}}{{\displaystyle {\sum }_{j=1}^n{\left(T_j-\underset{\_}{T}\right)}^2}}}$ , where $\underset{\_}{T}=\frac{1}{n}{\displaystyle {\sum }_{j=1}^n{T}_j}$