Adding scale bar to ggplot map

Question

I\'ve produced this map in ggplot2:

library(maptools); library(ggplot2)
data(wrld_simpl)
world <- fortify(wrld_simpl)
worldUk <- subset(wo         


        

Answer 1

I would suggest annotate(), which would allow you to draw segments of the proper length right in the plotting area. You could then add text above/below as a label.