如何从R中的计数数据绘制条形图？

Question

I have a data-frame 'x'

I want barplot like this

I tried

barplot(x$Value, names.arg = x$'Categorical variable')
ggplot(as.data.frame(x$Value), aes(x$'Categorical variable')

Nothing seems to work properly. In barplot, all axis labels (freq values) are different. ggplot is filling all bars to 100%.

Answer 1

You can try plotting using geom_bar(). Following code generates what you are looking for.

df = data.frame(X = c("A","B C","D"),Y = c(23,12,43))
ggplot(df,aes(x=X,y=Y)) + geom_bar(stat='identity') + coord_flip()

Answer 2

You have to use stat = "identity" in geom_bar() .

dat <- data.frame("cat" = c("A", "BC", "D"),
                  "val" = c(23, 12, 43))
ggplot(dat, aes(as.factor(cat), val)) +
  geom_bar(stat = "identity") +
coord_flip()

Answer 3

It helps to read the ggplot documentation. ggplot requires a few things, including data and aes() . You've got both of those statements there but you're not using them correctly.

library(ggplot2)
set.seed(256)

dat <- 
  data.frame(variable = c("a", "b", "c"), 
             value = rnorm(3, 10))

dat %>%
  ggplot(aes(x = variable, y = value)) +
  geom_bar(stat = "identity", fill = "blue") +
  coord_flip()

Here, I'm piping my dat to ggplot as the data argument and using the names of the x and y variables rather than passing a data$... value. Next, I add the geom_bar() statement and I have to use stat = "identity" to tell ggplot to use the actual values in my value rather than trying to plot the count of the number.