How do I annotate outside of horizontal bar plot in ggplot2

Question

I have been searching for a way to add text next to horizontal stacked bar plots but outside of the plotting area, but I can't seem to find a solution.

here is some example data and the plot:

df <- data.frame(x = c('A', 'A', 'B', 'B', 'C', 'C'),
                 y = c(3, 7, 5, 5, 6, 4),
                 z = c(1, 0, 1, 0, 1, 0),
                 a = c(40, 40, 50, 50, 60, 60))

ggplot() +
  geom_bar(data = df, aes(x = x, y = y, fill = z), stat = 'identity') +  
  coord_flip() +
  theme(
    panel.background = element_blank(),
    axis.line.y = element_blank(),
    axis.ticks.y = element_blank(),
    axis.line = element_line(colour = 'black'),
    legend.position = 'none')

What I would like to do is add the values of 'a' to the right of the horizontal bars. I have tried to do this with annotate but it results in the axis extending and also, for longer labels, part ends up being cut off.

I have also seen that coord_cartesian can be used to specify the range of interest on the axis and stop the label being clipped, but ggplot wont let me use it along with coord_flip.

How can I acheive the desired labels?

Answer 1

This gives me quite fair result:

  library(ggplot2)
  df <- data.frame(x = c('A', 'A', 'B', 'B', 'C', 'C'),
                   y = c(3, 7, 5, 5, 6, 4),
                   z = c(1, 0, 1, 0, 1, 0),
                   a = c(40, 40, 50, 50, 60, 60))

  ggplot(data = df, aes(x = x, y = y, fill = as.factor(z))) +
    geom_bar( stat = 'identity') +  
    coord_flip() +
    geom_text(aes( label = sprintf("%.1f",a), y= 10.5),  vjust = 1)+
    #guides(fill=FALSE)+
    theme(
      panel.background = element_blank(),
      axis.line.y = element_blank(),
      axis.ticks.y = element_blank(),
      axis.line = element_line(colour = 'black'),
      legend.position = 'none')+
    scale_y_continuous(breaks = seq(0,10,2))