ggplot2 Bar Graph From a Tally

A Tally

myTally <- data.frame(
  class = c("a", "b", "c"),
  tally = c(10, 15, 7)
)
myTally

##   class tally
## 1     a    10
## 2     b    15
## 3     c     7

Let’s make a bar graph where the height of each bar is the number of items in each value of class.

The Bar Graph

The trick is to set map y-position aesthetically to tally in your frame, and to use the "identity" option for the stat parameter (instead of its default value of "count"):

myTally %>% 
  ggplot(aes(x = class, y = tally)) +
  geom_bar(fill = "skyblue", stat = "identity")