Fig. 4
From: A novel method to detect the early warning signal of COVID-19 transmission
The early signals of COVID-19 in Canada. a Construct the country network by traffic information. b The early warning signal of the outbreak of COVID-19 in Canada between June 16, 2021 and October 17, 2021.The red line depicts the ARNN-LNE index calculated by the algorithm in “Methods”, whereas the blue line represents the daily news case of COVID-19, which was derived from raw data after smoothing filtering processing. The ARNN-LNE index can be considered an early warning signal if it exceeds this green line which stands for the threshold. The yellow circles are the formal signals, while the purple diamond denotes the local peak of daily new cases. c The detailed information about the nodes in this network