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Table 1 Summary of wavelet analysis, cross-correlation coefficient analysis, and Spearman’s rho results

From: A study of the correlation between dengue and weather in Kandy City, Sri Lanka (2003 -2012) and lessons learned

Parameters Wavelet analysis (MATLAB) SPSS
Sign of correlation and (lagging period in weeks) Cross-correlation coefficient Spearman’s rho
Dengue incidence vs. rainfall (in mm) Positive (7 weeks) −0.143 in 18 weeks (0.069 in 7 weeks, but below upper confidence level) −0.095; correlation is significant at the 0.05 level (two-tailed)
Dengue incidence vs. rainy days (days with rainfall >0.1 mm)* No wavelet coherence 0.146 in 7 weeks −0.058
Dengue incidence vs. rainy days (days with rainfall >0.3 mm)* Positive (7 weeks) 0.144 in 7 weeks −0.70
Dengue incidence vs. wet days (days with rainfall >1 mm)* Positive (7 weeks) 0.137 in 7 weeks −0.61
Dengue incidence vs. wet days (rainfall >3 mm)* Positive (7 weeks) 0.136 in 7 weeks −0.074
Dengue incidence vs. days with rainfall >20 mm Positive (7 weeks) −0.133 in 18 weeks (0.049 in 5 weeks, but below upper confidence level) −0.116; correlation is significant at the 0.01 level (two-tailed)
Dengue incidence vs. maximum temperature Positive (12 weeks) 0.202 in 14-week lag; 0.139 in 12-week lag −0.143; correlation is significant at the 0.01 level (two-tailed)
Dengue incidence vs. minimum temperature Positive (6 weeks) 0.166 in 7 weeks −0.035
Dengue incidence vs. average temperature Positive (11 weeks) 0.214 in 14 weeks −0.169; correlation is significant at the 0.01 level (two-tailed)
Dengue incidence vs. daytime humidity Positive (5 weeks) 0.158 in 7 weeks −0.038
Dengue incidence vs. nighttime humidity Positive (7 weeks) 0.137 in 7 weeks −0.135; correlation is significant at the 0.01 level (two-tailed)
Dengue incidence vs. average humidity Positive (5 weeks) 0.161 in 7 weeks (0.131 in 5 weeks) −0.066
Dengue incidence vs. wind run Negative (9 weeks) 0.181 in 20 weeks 0.150; correlation is significant at the 0.01 level (two-tailed)
-0.042 in 7 weeks
Dengue incidence vs. sunshine hours Positive (15 weeks) 0.130 in 18 weeks (0.113 in 15 weeks; 0.125 in 6 weeks) 0.014
  1. *The Sri Lankan department of meteorology defines a rainy day as a day with rainfall >0.3 mm (in some countries, it is >0.1 mm), and a wet day as a day with rainfall >1 mm. The Sri Lankan department of agriculture defines wet day as a day >3 mm rain. We have done calculations for all these definitions