This signal uses a rank-1 approximation, from a nonnegative matrix factorization approach, to identify an underlying signal that best reconstructs the Doctor Visits (doctor-visits:smoothed_cli), Facebook Symptoms surveys (fb-surveys:smoothed_cli), and Search Trends (ght:smoothed_search) indicators.…

This signal uses a rank-1 approximation, from a nonnegative matrix factorization approach, to identify an underlying signal that best reconstructs the Doctor Visits (doctor-visits:smoothed_cli), Facebook Symptoms surveys (fb-surveys:smoothed_cli), and Search Trends (ght:smoothed_search) indicators. It does not include official reports (cases and deaths from the jhu-csse source). Higher values of the combined signal correspond to higher values of the other indicators, but the scale (units) of the combination is arbitrary. Note that the Search Trends source is not available at the county level, so county values of this signal do not use it. Discontinued May 28, 2020.