Table 6 Performance Metrics.
Sr. No | Metric Equation | Range | Unit |
|---|---|---|---|
1 | \({R}^{2}= 1-\frac{{\Sigma }_{i=1}^{N}{\left({x}_{i}-{\widehat{x}}_{i}\right)}^{2}}{{\Sigma }_{i=1}^{N}{\left({x}_{i}-\overline{x }\right)}^{2}}\) | 0 – 1 (1 = perfect fit) | Unitless |
2 | \(RMSE= \sqrt{\frac{1}{N}{\sum }_{i=1}^{N}{\left({x}_{i}-{\widehat{x}}_{i}\right)}^{2}}\) | 0 = Best Result | MPa |
3 | \(NRMSE= \frac{RMSE}{\overline{x} }=\frac{ \sqrt{\frac{1}{N}{\sum }_{i=1}^{N}{\left({x}_{i}-{\widehat{x}}_{i}\right)}^{2}}}{\overline{x} }\) | 0 = Best Result | Unitless |
4 | \(MAE= \frac{1}{N}{\sum }_{i=1}^{N}\left|{x}_{i}-{\widehat{x}}_{i}\right|\) | 0 = Best Result | MPa |
5 | \(d= 1-\frac{{\Sigma }_{i=1}^{N}{\left({x}_{i}-{\widehat{x}}_{i}\right)}^{2}}{{\Sigma }_{i=1}^{N}{\left(\left|{\widehat{x}}_{i}-\overline{x }\right|+\left|{x}_{i}-\overline{x }\right|\right)}^{2}}\) | 0 – 1 (1 = perfect agreement) | Unitless |
