Figure 2
Average spectra and outliers. (a) Average micro-FTIR blood serum spectra for negative (black line) and positive (red line) groups. The vertical lines represents the main vibrational bands contributing to discrimination of groups (see band assignments on Table 2). (b) Outliers identification by inspection of \(Q^{2}\) residuals (reduced) versus \(T^{2}\) Hotelling’s. The outliers were indicated by “*”. Dashed horizontal lines and vertical lines represent confidence limits of 3% (Hotelling’s \(T^{2}\)) and 97% (Q residuals), respectively.
