Fig. 2
From: The short-term effects of air pollutants on influenza-like illness in Jinan, China
The wavelet coherence of ILI and all air pollutant concentrations. The thick black curve shows the 5% significance level against red noise. The thick black curve shows the 5% significant level against red noise. The cone of influence separating the regions with reliable and less reliable estimates is represented by the lighter pale colors. The color code for power ranges from blue (low power) to red (high power). X-axis denotes the time period and y-axis represents frequencies or scale. The relative phase relationship is shown as arrows (with ināphase pointing right, anti-phase pointing left). Arrows pointing to north-east and south-west mean the X is leading. Arrows pointing to north-west and south-east mean the y is leading