Specific spaces between bars in a barplot - ggplot2 - R

Question

I have a simple bargraph like the following

a<-data.frame(x=c("total","male","female","low education",
            "mid education","high education","working","not working"),
        y=c(80,30,50,20,40,20,65,35))
a$x<-as.character(a$x)
a$x<-factor(a$x,levels=unique(a$x))


ggplot(a,aes(x,y)) + 
geom_bar(stat="identity",fill="orange",width=0.4) +
coord_flip() +
theme_bw()

Now , because the levels of the x axis (flipped and now seems like y ) have a relation with each other e.g male and female represent sex breakdown , working and not working represent another breakdown etc., I want the axis to leave some space between each breakdown in order to point out these breakdowns.

I have tried some things with scale_x_discrete and its parameter break but it seems that this is not the way it goes . Any ideas ?

Answer 1

I don't know of a way to set different distances between bars in a barplot. However, you can add bars with height 0 and no label between the groups as follows:

a<-data.frame(x=c("total","a","male","female","b","low education",
                  "mid education","high education","c","working","not working"),
              y=c(80,0,30,50,0,20,40,20,0,65,35))
a$x<-factor(a$x,levels=unique(a$x))


ggplot(a,aes(x,y)) + 
   geom_bar(stat="identity",fill="orange",width=0.4) +
   coord_flip() +
   theme_bw() +
   scale_x_discrete(breaks=a$x[nchar(as.character(a$x))!=1])

Some remarks:

• a$x is a character from the start, so there is no need to call as.character on it.
• It only works, if the each "empty" bar has a different label. That's why I chose three different letters.
• scale_x_discrete is used to suppress the labels and tick marks.

The result looks as follows: