I first downloaded the world map using the maps package. After changing the names of some countries, I combined the longitude and latitude of the map and my data. The following is my code:
p.i<-ggplot(df.map.i,aes(x=long,y=lat,group=location_name))+
geom_polygon(aes(fill=case),color="black")+
coord_fixed(1.3)
