Как стартер, ковбой!
## some lonely cows
df<-data.frame(cows=c("4","9","113","1","2"),
fips =c(45001, 22001, 16001,19001, 29001))
## all Fips
maps::county.fips %>%
as_tibble %>%
extract(polyname, c("region", "subregion"), "^([^,]+),([^,]+)$") -> dfips
## some county maps & left_join
map_data("county") %>%
left_join(dfips) -> data
## more left_join
data<-left_join(data,df)
## character cows
data$cows<-as.numeric(as.character(data$cows))
### more cows
data[["cows"]][is.na(data[["cows"]])] <- 100
## even more random cows
data$cows<-ceiling(rnorm(length(data$cows),600,200))
## map with random, fictive cows
data %>% ggplot( aes(long, lat, group = group)) +
geom_polygon(aes(fill=cows)) +
coord_map() +
theme_void() +
scale_fill_viridis_c(option = "A")+
ggtitle("Fictive random cows of the United States of America", subtitle = "“In a county near YOU!”")