rggplot2stackedbarseries

ggplot stacked bar graph with bars relating to two different variables with percentages


I would like to create a stacked bar graph with ggplot where the heights of the bars depend on the values of one variable (voter turnout in %) and the stacks of the bars individually add up to 100% of another variable (voteshare in %). So for the year 1990 there was a voter turnout of 96.7 and the bar should be filled with the individual voteshares of each party, which add up to 100% (of the 96.7%). I look at the data of 3 parties and 3 years.

Here is my data:

party <- c("a", "b", "c", "a", "b", "c", "a", "b", "c") 
year <- c(1990, 1990, 1990, 1991, 1991, 1991, 1992,1992, 1992)
voteshare <- c(0,33.5, 66.5, 40.5, 39.0, 20.5, 33.6, 33.4, 33)
turnout = c(96.7,96.7,96.7, 85.05,85.05,85.05, 76.41, 76.41, 76.41)
df<- data.frame(parties, year, voteshare, turnout)

In addition, I would like to put the numbers of the individual voteshares and the total turnout inside the graph.

My approach so far:

ggplot(df, aes(x=year, y=interaction(turnout, voteshare), fill=party)) + 
    geom_bar(stat="identity", position=position_stack()) +
    geom_text(aes(label=Voteshare), vjust=0.5)

It's a mess.

Thanks a ton in advance!


Solution

  • I used a dplyr pipeline to:

    Code

    library(dplyr)
    library(ggplot2)
    
    df <- df %>%
      mutate(adj_vote = turnout * voteshare / 100) %>%
      filter(adj_vote > 0) %>%
      group_by(year) %>% 
      mutate(cum_vote = cumsum(rev(adj_vote)),
             vote_label = rev(voteshare))
    
    
    ggplot(df, aes(x=year, y=adj_vote, fill=party)) + 
      geom_bar(stat="identity", position=position_stack()) +
      geom_text(aes(label=vote_label, y = cum_vote), vjust=0.5)
    

    Output

    ggplot2 output