Fig. 4: Pearson correlation analysis between the percentage change in the city movement intensity (CMI) index derived from Weibo mobility data and Baidu Qianxi data.
From: Measuring Chinese mobility behaviour during COVID-19 using geotagged social media data
Lines with high transparency depict the original percentage change value, while lines with low transparency depict the smoothed value with a 7-day moving average method. The red vertical dashed line indicates January 20, 2020 (the national announcement of COVID-19 human-to-human transmission). The percentage change is calculated by comparing it to baseline days. The baseline days represent a normal value for that day of the week and are given as the median value over pre-pandemic periods (January 1 to January 19, 2020). r represents the Pearson’s correlation coefficient for the percentage change in the CMI index derived from Weibo mobility data and Baidu Qianxi data, while rc derived from Weibo mobility data corrected by the post-stratification method. ***represents the significance level of P < 0.001.
