Contact network generation

A contact network is a collection of several contact graphs at different times of day. In this framework, we generate contact graphs at 5-minute time steps for the entire population using activity-based simulated trajectories from calibrated models of the two cities. The contact graph, at any 5-minute time window, is created by a union of three subgraphs—Home, Activity or Transit. The Home graph consists of agents who share a home during the time window. The Activity graph comprises individuals who are performing an activity (Work, Education, Shopping or Other). The Transit graph consists of individuals who are traveling in a bus or train or waiting for the same. We assume that motorists make no contacts while en route to their destinations, hence they are not modeled in our contact graph. To facilitate an efficient representation of the contact graphs, we employ a hub-and-spoke transformation, which leverages on the sparseness of the graphs (Supplementary Figure ⁷).