Figure 4.

(a) Accuracy (as captured by the RMSE value) of the polynomial regression models as a function of the maximum polynomial degree considered in each model (see Sec. 2b)—as obtained for the training and test set, respectively. The optimal polynomial order is chosen as that for which the RMSE of the test set is minimum. (b) Comparison between the Young’s modulus values predicted by polynomial regression (with a degree of 3) and computed by molecular dynamics simulations.