Dengue incidence and wavelet power spectrum across geographic regions. The weekly number of dengue cases by date of symptoms onset reported through the surveillance system in Perú during the period 1994-2008 (square root transformed) in A) the entire country, C) jungle region, E) coast region, and G) mountain region and the corresponding wavelet power spectrum of the weekly series of dengue fever for B) the entire country, D) jungle region, F) coast region, and H) mountain region. The color code for power values ranges from dark blue, low values, to dark red, high values. Statistically significant areas (threshold of 5% confidence interval) in wavelet power spectrum (left panels) are highlighted with solid line; the cone of influence (region not influenced by edge effects) is also indicated. Finally, the right panels show the mean spectrum (solid blue line) with its significant threshold value of 5% (solid black line).