Fig. 3.
Biplot of the first two dimensions of multiple correspondence analysis on association between the presence (filled large dots) or absence (empty large dots) of symptoms and seropositivity (crosses) in all individuals aged 50 years or more with acute respiratory illness. The variables included in the analysis are colored according to the sum of cos2 of the variable on dimensions one and two. Grey and black small dots represent seronegative and seropositive individuals, respectively. Practices of gravity of seropositive and seronegative individuals are shown by squares surrounded by 95% confidence ellipses.