Using ggplot2 to plot percentages in bar chart.

That?s precisely what I?m trying to accomplish.

Shawn Way, PE

From: John Kane [mailto:jrkrideau at yahoo.ca]
Sent: Monday, December 05, 2016 4:47 PM
To: Shawn Way <SWay at meco.com>; r-help at r-project.org
Subject: Re: [R] Using ggplot2 to plot percentages in bar chart.

I've never seen   stat_bin used like that. What exactly is it supposed to
do. It looks like you are trying to label the %ages in each piece of the
bar.

On Monday, December 5, 2016 2:17 PM, Shawn Way <SWay at meco.com<mailto:
SWay at meco.com>> wrote:

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