Figure 2

Important features selected for sample classification: (a) features of subset 1 selected by t-tests with a significance threshold of 0.05. Blue circles represent features above the threshold (p); values are transformed by –log10; (b) Features of subset 2 selected by the VIP value (score above 1). Characteristics of the biomarker distribution in vase samples, including a grouped histogram of biomarker occurrences in samples from the cemetery and settlement (c) and a clustered heatmap of biomarkers for which the minimum absolute difference between the two groups of vases in histogram was at least 2. Additionally, the frequently occurring lactic acid was considered (d).