Fig. 1. Schematic diagram (a) and photogragh (b) of LIBS device^[8]

Fig. 2. Photograph of ceramic sherd samples. (a) Ancient ceramics; (b) Modern ceramics

Fig. 3. LIBS spectra of three ceramic sherd samples. (a) Glaze; (b) Clay

Fig. 4. Curve of contribution with the number of principal components

Fig. 5. Load plots of characteristic spectral lines of the 10 elements

Fig. 6. Plot of principal component scores of the glaze spectra of 6 ancient ceramic sherd samples

Fig. 7. Confusion matrix of the classification results of the 6 ancient ceramic sherd samples

Fig. 8. Plot of principal component scores of clay spectra of Yaozhou samples

Fig. 9. Scatter plot of LDA obtained for the Yaozhou samples according to the first three discriminant functions. (a) Training set; (b) Test set

Fig. 10. Terra cotta PCA scores plot of 18 ceramic sherds obtained from the first three principal components

Fig. 11. LDA scatter plot obtained from the first three discriminant functions. (a) Training set; (b) Test set

Fig. 12. Confusion matrix for classification results of the 18 ceramic sherd samples