Figure 1
From: Accounting for seasonal patterns in syndromic surveillance data for outbreak detection

Average daily respiratory counts, by week (top) Real data; (middle) Data simulated from Eq. (1) (nonhierarchical model with larger-than-Poisson variance); (bottom) Data simulated from Eq. (2) (hierarchical model with larger-than-Poisson variance). In all 3 plots, the weekly averages begin on Jan 31, 1994 and end on May 31, 2003. The smooth curve is the Eq. (1) fit to all nine years of respiratory data.