**Figure 2:** Figure 2: PCA models obtained using different bucket widths, 0.1 ppm, 0.05
ppm and 0.01 ppm (top to bottom). All samples are color coded using black for
healthy and blue for infected. A) Confidence plot for the model, showing that
all samples used are well described with the model. B) Deviation plot, showing
the distribution of the distances of the samples from the model. For the model
with the bucket width 0.01 ppm a equal distribution for healthy and infected
is observed. C) Number of PCs explaining the data diversity, values shown
indicate variance explained using PC1 and >95% (blue). D) 2D projections
plotting the PCs 1×2, 1×3, 4×2 and 2×3. The plots 1×2, 4×2 and 2×3 show good
separation of the samples into healthy and infected. E) 2D projections plotting
the buckets influence on the localization of samples in the previous plot. Whilst
most buckets accumulate on one point, 8 can be identified that are responsible
for the separation seen in the previous plot. |