Sorting a boxplot based on median value

Question

I\'d like to use R to make a series of boxplots which are sorted by median value. Suppose then I execute:

boxplot(cost ~ type)

This would g

Answer 1

Check out ?reorder. The example seems to be what you want, but sorted in the opposite order. I changed -count in the first line below to sort in the order you want.

  bymedian <- with(InsectSprays, reorder(spray, -count, median))
  boxplot(count ~ bymedian, data = InsectSprays,
          xlab = "Type of spray", ylab = "Insect count",
          main = "InsectSprays data", varwidth = TRUE,
          col = "lightgray")