adding sample size labels to x axis ticks for weighted survey in ggplot?

Question

I have a dataframe generated from a weighted survey of a list of countries and their subgroups

Sampling Weights	Country	Gender	Percentage	n
400	A	Male	20	100
600	A	Female	80	70
300	B	Male	30	45
500	B	Female	70	70
100	C	Male	40	100
50	C	Female	60	70

Using ggplot, I want to create a bar chart that has the n values of the subgroup in the x axis ticks. The x axis would be the countries with the male/female subgroups plus sample size and the y axis would be the percentage.

It would be too tedious to rename each subgroup name and add the sample size in parentheses so I was wondering if there was a faster way to do so while also being able to wrap the text around.

So

Male (n = 100) Female (n = 70) Country A

Keep in mind some of these Country names are actually long in the real data set so the labels would get crowded.

Answer 1

library(dplyr); library(ggplot2)

df1 %>%
  ggplot(aes(Gender, Percentage)) +
  geom_col() +
  geom_text(aes(y = 0, label = paste("n = ", n)), vjust = 1.5) +
  scale_x_discrete(name = NULL) +
  facet_wrap(~Country, strip.position = "bottom") +
  theme(strip.placement = "outside", strip.background = element_blank()) 

Or:

df1 %>%
  mutate(Gender2 = paste0(Gender, " (n = ", n, ")")) %>%
  ggplot(aes(Gender2, Percentage)) +
  geom_col() +
  scale_x_discrete(name = NULL) +
  facet_wrap(~Country, strip.position = "bottom", scales = "free_x") +
  theme(strip.placement = "outside", strip.background = element_blank())