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

Beware of missing values, you have to add na.rm = TRUE for it to work. If not, the code simply doesn't work. It took me hours to found that out.

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