R: How to order boxplots by variance?-CodePudding

Is it possible to order box plots in R by their variance?

rm(list = ls())
library(datasets)
library(ggplot2)

data(airquality)
airquality$Month <- factor(airquality$Month,
                           labels = c("May", "Jun", "Jul", "Aug", "Sep"))


p10 <- ggplot(airquality, aes(x = Month, y = Ozone))  
        geom_boxplot()
p10

How can I make it so that the variable with the most variation would be on the left of this plot?

Any help at all would be greatly appreciated!

CodePudding user response：

With reorder you could do:

library(ggplot2)

data(airquality)
airquality$Month <- factor(airquality$Month,
                           labels = c("May", "Jun", "Jul", "Aug", "Sep"))


ggplot(airquality, aes(x = reorder(Month, Ozone, function(x) -var(x, na.rm = TRUE)), y = Ozone))  
  geom_boxplot()
#> Warning: Removed 37 rows containing non-finite values (stat_boxplot).

CodePudding user response：

Here's a full tidyverse-based reprex

library(tidyverse)

airquality %>%
  group_by(Month) %>%
  mutate(var = var(Ozone, na.rm = TRUE)) %>%
  ungroup() %>%
  mutate(Month = fct_reorder(month.abb[Month], -var)) %>%
  ggplot(aes(x = Month, y = Ozone))  
  geom_boxplot()
#> Warning: Removed 37 rows containing non-finite values (stat_boxplot).

^{Created on 2022-04-18 by the reprex package (v2.0.1)}