fig8

Figure 8. A performance comparison chart of 12 machine learning model test sets constructed based on the optimal strength feature subset. ML: Machine learning; R²: the coefficient of determination; RMSE: root mean square error; Bagging: bootstrap aggregating; RF: random forest; GBRT: gradient boosting regression tree; ExtraTree: extremely randomized tree; AdaBoost: adaptive boosting; LGBM: light gradient boosting machine; XGBoost: eXtreme gradient boosting; KNN: K-nearest neighbor; DT: decision tree; ANN: artificial neural network; SVR: support vector regression.