Spatiotemporal Dynamics of Dengue Epidemics, Southern Vietnam
Figure 3. . Wavelet analysis of dengue periodicity, 2001–2010. A) Left panel: wavelet power spectrum (WPS) of the aggregate monthly dengue time series for southern Vietnam (square-root transformed, normalized, and trend suppressed). Colors code for increasing spectrum intensity, from blue to red; dotted lines show statistically significant area (threshold of 95% CI); the black curve delimits the cone of influence (region not influenced by edge effects). Right panel: Mean spectrum (solid line) with its threshold value of 95% CI (dotted line) for the aggregate time series. B) WPS and mean spectrum for Binh Duong Province. C) WPS and mean spectrum for Bac Lieu Province. D) WPS and mean spectrum for Ca Mau Province. The wavelet power spectra for Binh Duong, Bac Lieu, and Ca Mau Provinces are shown because they were the only 3 provinces in which a dominant multiannual cycle was detected.