Visualisation and Exploration of Scientific Data Using Graphs - Data Mining: Theory, Methodology, Techniques, and Applications - page 23

Fig. 4. The same graph as Fig. 1, but with edge colouring changes to indicate similarity of chromium between sites. Darker edges are
those that are better “explained” by chromium patterns (see text for details). Edges within clusters are generally well explained (similar
within-cluster chromium values), whereas the inter-cluster edges indicate dissimilar chromium values. These results, and similar results
with other metal variables, suggest that species differences between the two bays may be related to heavy metal concentrations.