Lec18_solutions.R

library(dplyr)
library(ggplot2)
library(rgdal)
library(leaflet)

# Set your working directory to where the folder that contains your shapefiles is at:
VT <- rgdal::readOGR("VT_shapefiles/tl_2015_50_tract.shp", layer = "tl_2015_50_tract")

# The variable in ALAND exists here, i.e. you don't need to join anything
VT@data

leaflet(VT) %>%
  addTiles() %>% 
  addPolylines(color="black", weight=1) %>% 
  addPolygons(
    stroke = FALSE, fillOpacity = 0.5, smoothFactor = 0.5,
    color = ~colorQuantile("YlOrRd", VT$ALAND)(ALAND)
  )