[R] Using ggplot2 to plot percentages in bar chart.

[Shawn Way]

I have the following data in which I'm trying to summarize in a stacked bar plot showing the percentages as a label in the bar.

The data is as follows:

> head(data)
  MASTERPAK2LT MASTERPAK4LT MASTERPAK7LT MASTERPAK10LT MASTERPAK22LT
1            X            X            X             X             X
2            C            C            C             X             X
3            C            C            C             X             X
4            U            U            X             X             X
5         <NA>            U            X             X             X
6         <NA>         <NA>            X          <NA>          <NA>

It is then transformed using dplyer:

> d2 <- data %>%
    gather(Model,Status) %>%
    group_by(Model,Status) %>%
    summarise(count=n()) %>%
    mutate(perc=count/sum(count))

giving 
> head (d2)
Source: local data frame [6 x 4]
Groups: Model [2]

          Model Status count       perc
          <chr>  <chr> <int>      <dbl>
1 MASTERPAK10LT      C     8 0.21052632
2 MASTERPAK10LT      X    29 0.76315789
3 MASTERPAK10LT   <NA>     1 0.02631579
4 MASTERPAK22LT      C     6 0.15789474
5 MASTERPAK22LT      U     1 0.02631579
6 MASTERPAK22LT      X    30 0.78947368

I then try to plot this using ggplot using 

plt <- ggplot(d2,aes(x=Model,y= perc,fill=Status)) +
    geom_bar(stat="identity") +
    labs(y="Percent Complete") +
    stat_bin(geom = "text",
             aes(label=paste(round(perc*100),"%")),
             vjust=5) +
    scale_y_continuous(labels = percent)

but I get the error:

Error: stat_bin() must not be used with a y aesthetic.

When I leave out the stat_bin, I get the correct bar chart, but without the labels.  Can someone please help me understand what is causing the error above?


Thank you kindly,

Shawn Way, PE