ggplot: How to add a certain percentage to the top of the pillars of a histogram

Question

I need to replicate a certain format of a histogram/barchart. I already did some good modification with ggplot in order to group the categorial x-variable and specifiy the colors with HEX.

Here is what I try to plot/replicate:

Here is a MWE for my data structure:

sex <- sample(0:1, 100, replace=TRUE)
group <- sample(2:5, 100, replace=TRUE)
data <- data.frame(sex, group)

library(ggplot2)
ggplot(data, aes(x = group, group=sex, fill=factor(sex) )) +
  geom_histogram(position="dodge", binwidth=0.45) +                      
  theme(axis.title.x=element_blank(), axis.title.y=element_blank()) +    
  guides(fill=guide_legend(title="sex")) +                        
  scale_y_continuous(labels = scales::percent_format())   +              
  scale_fill_manual(values=c("#b6181f", "#f6b8bb"))

I get:

Small things I can't handle are:

replace the factor labels on the x-axis, there might be a problem with my histogram-approach, but I also found no practical way with a bar-chart
round the percentage-digits, no decimals for percentages

But most important is, that I don't know how to add a single percentage-value for one group, one sex to the top of each bar..

I am looking forward for some advice :)

Alright I have rollbacked your edits, but you can still see the other versions by clicking on the revisions. — Axeman

giovannotti giovannotti · Accepted Answer · 2018-01-05T13:21:19

First of all I would treat your x-axis data as factors and plot it as bars. Getting percentage value text to the bar top look this question: Show % instead of counts in charts of categorical variables. Futhermore the y-axis percent values aren't a question of rounding, they actually are no percentage values. y = ..prop.. solves that.

Are you looking for that (I summed everything up)?

sex <- sample(0:1, 100, replace=TRUE)
group <- sample(2:5, 100, replace=TRUE)
data <- data.frame(sex, group)

labs <- c("Score < 7", "Score\n7 bis < 12", "Score\n12 bis < 15",
          "Score\n15 bis < 20","Score >= 20")

ggplot(data, aes(x = as.factor(group), y = ..prop.., group = sex, fill = factor(sex) )) +
  geom_bar(position = "dodge") +
  geom_text(aes(label = scales::percent(..prop..)), 
            position = position_dodge(width = 0.9), stat = "count", vjust = 2) +
  labs(x = NULL, y = NULL) +
  guides(fill = guide_legend(title = "sex")) +                        
  scale_y_continuous(labels = scales::percent_format())   +              
  scale_fill_manual(values=c("#b6181f", "#f6b8bb")) +
  scale_x_discrete(labels = labs)

ggplot: How to add a certain percentage to the top of the pillars of a histogram

1 Answers