When the sample size behind each category is highly variable, it can be great to represent it through the box widths.

First calculate the proportion of each level using the
`table()`

function. Using these proportions will make the
box twice bigger if a level is twice more represented. Then give
these proportions to the `width`

argument when you call
the `boxplot()`

function.

```
# Dummy data
names <- c(rep("A", 20) , rep("B", 8) , rep("C", 30), rep("D", 80))
value <- c( sample(2:5, 20 , replace=T) , sample(4:10, 8 , replace=T),
sample(1:7, 30 , replace=T), sample(3:8, 80 , replace=T) )
data <- data.frame(names,value)
# Calculate proportion of each level
proportion <- table(data$names)/nrow(data)
#Draw the boxplot, with the width proportionnal to the occurence !
boxplot(data$value ~ data$names , width=proportion , col=c("orange" , "seagreen"))
```