Table 3. Parameters of DD-SIMCA models and performances in terms of sensitivity and specificity.
| Metrics | a priori Ciprofloxacin model | a posteriori Ciprofloxacin model | a priori Metronidazole model | a posteriori Metronidazole model |
|---|---|---|---|---|
| Spectral range | 961–1624 nm | 961–1624 nm | 961–1624 nm | 961–1624 nm |
| Preprocessing | SNV, SG (1, 2,15) | SNV, SG (1, 2,15) | SNV, SG (1, 2,15) | SNV, SG (1, 2,15) |
| α | 0.01 | 0.01 | 0.01 | 0.01 |
| Number of PC | 2 | 3 | 2 | 5 |
| Median Sn Cal (% of spectra) (95% CI) | 99.5 (97.9–100) | 98.4 (96.3–99.5) | 97.4 (95.3–99.0) | 97.4 (95.3–99.5) |
| Median Sn Val (% of spectra) (95% CI) | 96.7 (91.1–100) | 94.4 (88.9–97.8) | 88.9 (81.1–97.8) | 88.9 (80.0–96.7) |
| Median Sn test (% of samples) (95% CI) | 98.0 (90.0–100) | 100 (99.3–100) | 75.4 (68.3–93.7) | 100 (97.9–100) |
| rejected non-members samples/total number of non-members samples (95% CI) | 5/5 (5–5) | 5/5 (5–5) | 4/4 (4–4) | 4/4 (4–4) |
SNV = Standard Normal Variate
SG = Savitzky-Golay derivative (derivative order, polynomial order, window size)
Sn = Sensitivity
CI = confidence interval delimited by the 2.5th and 97.5th percentile of the empirical distribution obtained by bootstrap.