Percentage labels in a bar plot

Question

I want to produce a graphic similar to this:

relative frequency

I started with this code:

library(ggplot2)
library(scales) #needed for labels=percent

var1 <- sample(0:20,78,replace = TRUE)

var2 <- cut(var1, breaks = seq(0,20,5),include.lowest = TRUE)
df<-as.data.frame(var2)

ggplot(df, aes(x= var2)) + 
      geom_bar(aes(y = ..prop..,group=1),fill="dodgerblue3")+
      scale_y_continuous(labels=percent)+
      labs(x = NULL,y = NULL)+
      theme(axis.ticks.x = element_blank(),
            axis.text = element_text(size=7))

But I couldn't put the labels in the plot.

I tried to follow this example:

ggplot(df, aes(x= var2,  group=1)) + 
  geom_bar(aes(y = ..density..)) +
  geom_text(aes( label = format(100*..density.., digits=2, drop0trailing=TRUE),
                 y= ..density.. ), stat= "bin", vjust = -.5) +
  scale_y_continuous(labels=percent)

But I obtained this error (I use ggplot2-version 2.0.0):

Error: StatBin requires a continuous x variable the x variable is discrete. Perhaps you want stat="count"?

Finally I made the plot with this code:

per <- df %>% group_by(var2) %>% summarise(freq = n()/nrow(df))

ggplot(data=per, aes(x=var2,y=freq)) +
      geom_bar(stat="identity",fill="dodgerblue3")+
      geom_text(aes(label=percent(freq)),vjust=1.5,colour="white")+
      scale_y_continuous(labels=percent)+
      labs(x = NULL,y = NULL)+
      theme(axis.ticks.x = element_blank(),
            axis.text = element_text(size=7))

However, is it possible to make it like this example, without the need for the per dataframe and directly in ggplot?

RHA RHA · Accepted Answer · 2016-02-20T15:42:09

You could try this, which is taken from here and customized.

ggplot(df, aes(factor(var2))) +
  geom_bar(fill="dodgerblue3")+
  labs(x = NULL,y = NULL)+
  stat_bin(aes(label = paste(prop.table(..count..) * 100, "%", sep = "")),
           vjust = 1, geom = "text", position = "identity", color ="white")

giving:

EDIT:

In the new ggplot 2.0.X version, stat_countshould be used and not stat_bin. From the help

stat_count, which counts the number of cases at each x posotion, without binning. It is suitable for both discrete and continuous x data, whereas stat_bin is suitable only for continuous x data.

   ggplot(df, aes(factor(var2))) +
      geom_bar(fill="dodgerblue3")+
      labs(x = NULL,y = NULL)+
      stat_count(aes(label = paste(prop.table(..count..) * 100, "%", sep = "")),
               vjust = 1, geom = "text", position = "identity", color ="white")

Percentage labels in a bar plot

1 Answers