Fig. 4: Loading plot PC1 and PC2. | npj Science of Food

Fig. 4: Loading plot PC1 and PC2.

From: Residues on unglazed Roman pottery: extraction of organic spectral signatures via ATR-FTIR and machine learning

Fig. 4: Loading plot PC1 and PC2.

The different colour line of the absorption bands is due to the PC they belong to, black for PC1 [61%] and red for PC2 [30%]. The figure highlights both specific bands and spectral ranges of interest. Green shaded zones are ascribed to organic contributions of lipids; red shaded zones are the absorptions of carbonates, while yellow stripes are silicates. The grey-shaded region corresponds to the hydroxyl stretching band, which is indicative of ageing.

Back to article page