Table 1 Internal and external validation metrics for the single PCM models
Parameters | RF | SVM | GBM |
|---|---|---|---|
\({R}_{CV}^{2}\) | 0.89 | 0.54 | 0.92 |
\({RMSE}_{CV}\) | 0.382 | 1.11 | 0.317 |
\({R}_{test}^{2}\) | 0.62 | 0.29 | 0.57 |
\({R}_{0\, test}^{2}\) | 0.62 | 0.09 | 0.55 |
\(Q{}_{1}{}^{2}test\) | 0.62 | 0.07 | 0.53 |
\(Q{}_{2}{}^{2}test\) | 0.62 | 0.07 | 0.54 |
\(Q{}_{3}{}^{2}test\) | 0.67 | 0.18 | 0.60 |
\({RMSE}_{test}\) | 0.65 | 1.01 | 0.71 |
\(MAE\) | 0.46 | 0.84 | 0.54 |
\(\frac{\left({R}_{test}^{2}-{R}_{0\, test}^{2}\right)}{{R}_{test}^{2}} <0.1\) | 0.0003 | 0.689 | 0.016 |
0.85 ≤ k ≤ 1.15 | 1.0005 | 1.030 | 0.983 |