Table 1.
The model parameters of PCA and SIMCA.
| Model | Number | PCs | R2X | Q2 | AUC |
|---|---|---|---|---|---|
| PCA | 141 | 6 | 0.995 | 0.981 | - |
| SIMCA (AO) | 15 | 7 | 0.996 | 0.886 | 1.000 |
| SIMCA (AO-SO) | 42 | 6 | 0.994 | 0.975 | 0.993 |
| SIMCA (AO-CO) | 42 | 5 | 0.993 | 0.974 | 0.963 |
| SIMCA (AO-RO) | 42 | 5 | 0.998 | 0.945 | 0.997 |
Note: PCs: principle components, R2X: the measurement of fit for the PCA or SIMCA model, Q2: the measurement of prediction, which is calculated through cross validation to evaluate the predictive ability of the model. AUC (area under curve) is the area enclosed by the coordinate axis under the ROC (receiver operating characteristic) curve.