ggplot/mapping US counties — problems with visualization shapes in R

Question

So I have a data frame in R called obesity_map which basically gives me the state, county, and obesity rate per county. It looks more or less like this:

obesi         


        

Answer 1

I think all you needed to do was reorder the map.county variable like you had for the map.data variable previously.

....
map.county <- merge(county.obesity, map.county, all=TRUE)

## reorder the map before plotting
map.county <- map.county[order(map.data$county),] 

## plot
ggplot(map.county, aes(x = long, y = lat, group=group, fill=as.factor(value))) + geom_polygon(colour = "white", size = 0.1)