Figure 3
Daily flags from the CUSUM algorithm for k = 0.25, 0.50, 1, 1.5, and 2 applied to hospital S's unspecified infection daily counts during the winter of 2002. Green lines show the smoothed values for unspecified infection daily counts from the given hospital. Flagging times are also represented along the time axis with vertical lines that are color coded to the symbol. Note that the vertical axis is on a square root scale because of its variance stabilizing properties.