Ordering geom_bar() without a y defined variable

Question

Is there a way to order the bars in geom_bar() when y is just the count of x?

Example:

ggplot(dat) +
  geom_bar(aes(x = feature_1)) 

I tried using reorder() but it requires a defined y variable within aes().

Answer 1

Made up data:

dfexmpl <- data.frame(stringsAsFactors = FALSE,
         group = c("a","a","a","a","a","a",
                   "a","a","a","b","b","b","b","b","b","b","b","b",
                   "b","b","b","b","b","b"))

plot code - reorder is doing the work of arranging by count:

dfexmpl %>%
group_by(group) %>%
mutate(count = n()) %>%
ggplot(aes(x = reorder(group, -count), y = count)) +
geom_bar(stat = "identity")

results in: