Add count to each bar in ggplot bar chart-CodePudding

I have a large dataset, which can be exemplified using the below mwe

df <- data.frame("x" = c(1,1,1,2),"value" = c(4,3,5,1), "groupA" = c("A","B","A","B"), "groupB" = c("X","Y","Y","Y"))
df$value <- ifelse(df$groupB == "Y", -df$value, df$value)

I need to plot this, where one group yields fill, another whether it is above or below the x-axis. This can be done as follows:

ggplot(df,aes(x=x,y=value,fill=groupA)) 
    geom_bar(stat="identity")

This yields the sum of values in each groupB above and below zero, and color codes the bars nicely:

mwe bar chart

However, I also need the count in each instance printed as labels above each bar. Using

As you can see the position of the label is defined by the count. I have tried to set y=value, or y=5 (as an example) but this results in an error message.

How can I solve this?

(edited after zx8754 responded)

CodePudding user response：

I mean, it's not pretty, but it works...

library(dplyr)
library(ggplot2)
df %>% 
  group_by(x) %>% 
  mutate(count = ifelse(row_number() == 1, n(), NA)) %>% 
  ggplot(aes(x = x, y = value,fill = groupA)) 
    geom_col()  
    geom_text(aes(label = count, x = x, y = value))

Returns:

CodePudding user response：

If I understand the problem correctly we can use nudge:

ggplot(df,aes(x=x,y=value,fill=groupA)) 
  geom_bar(stat="identity") 
  geom_text(aes(label=..count..,group=x,y=..count..),
  nudge_y = c(1.4,3.3), stat="count")