Fig. 6

Classification of all the cities obtained with a KEGG-based functional profiles and b CARD-based functional profiles using a(t-SNE) [39] plot. Ilorin and Ofa, two physically close cities in Nigeria (connected by a train) map close to each other. New York, not close to Boston, and Lisbon, not close to Porto cluster apart in the plot. Hamilton and Auckland, both New Zealand cities connected by a train, also map together