How to apply ascending order within groups in bar plots

June 26, 2023

I have data frame like dat, and I wanted to graph region-wise grouped bar plots in a way that each region is ordered from low to high. I have checked other similar questions but I couldn’t find a solution to my problem. Would appreciate if someone could advise me how to handle it.

dat <- tribble(
  ~Country, ~Region, ~var,
  "Jordan", "MENA", 42,
  "Iran", "MENA", 26,
  "Turkey", "ECA", 37,
  "Pakistan", "AP", 42,
  "Indonesia", "AP", 84,
  "Bangladesh", "AP", 24,
  "Israel", "MENA", 65
)

dat %>%
  mutate(across(.cols = Region, .fns = ~readr::parse_factor(.x, 
                                                            levels = c("AP", "ECA", "MENA"), 
                                                            ordered = TRUE))) %>%
  ggplot(aes(x = as.factor(Country), y = var, fill = Region)) +
  geom_bar(stat="identity", position = "dodge")

>Solution :

You could order the factor within your region based on the levels order of your factor like this:

library(tidyverse)

dat %>%
  mutate(across(.cols = Region, .fns = ~readr::parse_factor(.x, 
                                                            levels = c("AP", "ECA", "MENA"), 
                                                            ordered = TRUE))) %>%
  ggplot(aes(x = factor(Country, levels = unique(Country[order(Region, var)]), ordered = TRUE), y = var, fill = Region)) +
  geom_bar(stat="identity", position = "dodge")