Trip duration drives shift in travel network structure with implications for the predictability of spatial disease spread
Fig 3
Distribution of node strength and node centrality for models with different trip duration intervals and changepoint analysis showing which trip durations constitute shifts in network topology.
The empirical distributions of A) node strength (weighted degree per node) and B) node closeness (total weighted distance from all nodes) are plotted for four duration-restricted subnetworks which include trips of 1) 0–1 days, 5) 5–7 days, 11) 2–3 months, and 20) 11–12 months. C) The joint distribution of ηstrength and ηclose which measures the amount of network heterogeneity and structure based on the distributions of node strength and node closeness respectively. Each point represents one of the duration-restricted subnetworks and is colored according the duration interval shown in the color key to the right. The multivariate changepoint algorithm identified two significant shifts in network topology based on the joint distribution of ηstrength and ηclose that are placed at 5 and 60 days trip duration. The three nominal classes delineated by these thresholds are indicated by a circle for the heterogeneous class (1–5 days), a triangle for the homogeneous class (>60 days), and a square for intermediate class (6–60 days).