Table 4 Overview of assessment measures for regression analysis.

From: Regression machine learning-based highly efficient dual band MIMO antenna design for mm-Wave 5G application and gain prediction

Metric

Equation

Mean absolute error (MAE)

\(\frac{1}{{\text{n}}}\mathop \sum \nolimits_{{{\text{i}} = 1}}^{{\text{n}}} \left| {\text{y}_{\text{i}} - \hat{\text{y}}_{\text{i}} } \right|\)

Mean squared error (MSE)

\(\frac{1}{{\text{n}}}\mathop \sum \nolimits_{{{\text{i}} = 1}}^{{\text{n}}} \left( {\text{y}_{\text{i}} - \hat{\text{y}}_{\text{i}} } \right)^{2}\)

Root mean squared error (RMSE)

\(\sqrt {\frac{1}{{\text{n}}}\mathop \sum \nolimits_{{{\text{i}} = 1}}^{{\text{n}}} \left( {\text{y}_{\text{i}} - \hat{\text{y}}_{\text{i}} } \right)^{2} }\)

R-square

\(1 - \frac{{\mathop \sum \nolimits_{{{\text{i}} = 1}}^{{\text{N}}} \left( {\text{y}_{\text{i}} - \hat{\text{y}}_{\text{i}} } \right)^{2} }}{{\mathop \sum \nolimits_{{{\text{i}} = 1}}^{{\text{N}}} \left( {\text{y}_{\text{i}} - \hat{\text{y}}_{\text{i}} } \right)^{2} }}\)

Variance score

\(1 - \frac{{Var\left( {y - \hat{y}} \right)}}{Var\left( y \right)}\)