Fig. 1. The nuclear symmetry energy (a) and its slope parameter (b) plotted as a function of density

Fig. 2. The results of 66 newly measured nuclei appeared in the AME2020 mass evaluation

Fig. 3. Δb dependence of the input grid dimension n

Fig. 4. Number in each cell denotes Δb for the testing data (generated with the vertical labeled mode) by using the training data (generated with the horizontal labeled mode). The left panels (right panels) present the results of the first (second) type of characteristic quantity.

Fig. 5. Confusion matrix for the five-class classification task

Fig. 6. Distributions of the predicted symmetry energy slope parameter L(ρ₀)(a, b) The results obtained with 4 and 30 observables, respectively