如何根据此列联表执行此操作?我不完全确定如何根据我制作的指标表(犯罪)在R中创建自定义图例.

R中可重现的代码:
require(maps)
set.seed(123)
# randomly assign 2 variables to each state
mappingData <- data.frame(state = tolower(rownames(USArrests)),
iceCream = (sample(c("Likes Ice Cream","Doesn't Like Ice Cream"),50, replace=T)),
hotDogs = (sample(c("Likes Hot Dogs","Doesn't Like Hot Dogs"),50, replace=T)))
# create a 'legend' key for an indicator variable
mappingDataDF<-data.frame(
expand.grid(iceCream=c("Likes Ice Cream","Doesn't Like Ice Cream"),
hotDogs=c("Likes Hot Dogs","Doesn't Like Hot Dogs")),
indicator=c("0","1","2","3"))
mappingData<-mappingData %>% inner_join(mappingDataDF)
mappingDatam <- reshape2::melt(mappingData, id = 1)
states_map <- map_data("state")
ggplot(mappingData, aes(map_id = state)) +
geom_map(aes(fill = indicator), map = …Run Code Online (Sandbox Code Playgroud)