R實現pm2.5地圖數據展現

使用rvest包抓取pm2.5靜態頁面數據，使用leafletCN包實現pm2.5數據的地圖展現，代碼以下所示：

library(rvest)
library(leafletCN)
Sys.setlocale("LC_CTYPE","eng")
doc = read_html("http://www.pm25s.com/cn/rank/")
cities = doc %>% html_nodes(".cityrank a") %>%
  html_text()
AQI = doc %>% html_nodes("span[class^='lv']") %>%
  html_text() %>% .[c(F,F,T)] %>% as.numeric
dat = data.frame(city=cities,AQI=AQI)
dat
geojsonMap(dat,"city",
           popup = paste0(dat$city,":",dat$AQI),
           palette = "Reds",legendTitle = "AQI")

執行結果以下