The data source is from the built-in R dataset: USArrests.
The map displays the murder rates per 100,000 in each state.
I am trying to communicate the murder rate by state.
I thought murder rates tell more the violence of a state than rapes and assault. I could’ve shown more information in the map, but I chose to keep it simple. I chose to use the maps library to make this process easier.
data(USArrests)
crimes <- data.frame(state=tolower(rownames(USArrests))
, USArrests)
library(maps)
library(ggplot2)
gg <- ggplot(crimes, aes(map_id=state, fill=Murder))
gg <- gg + geom_map(map=map_data("state"))
gg <- gg + expand_limits(x=map_data("state")$long, y=map_data("state")$lat)
gg+labs(title="Murder rates per 100,000 in 1973", x="longitude", y="latitude")