Creating a half-donut, or parliamentary seating, chart

Question

I\'d like to create a chart displaying the size of the seats to a parliament, such as the one below, in ggplot2. My main problem is, essentially, how do I turn a donut chart to

Answer 1

Would this work for you?

ggplot(df, aes(fill = Party, ymax = ymax, ymin = ymin, xmax = 2, xmin = 1)) + geom_rect() + 
  coord_polar(theta = "y",start=-pi/2) + xlim(c(0, 2)) + ylim(c(0,2))

Basically you just set the ylim to be 2x your max so it only plots it on half. In this case we set the y limits to be from 0 to 2. Then you can offset the start in coord_polar(start=) to get it in proper place.