Add color segments to location on a map plot by using lat and lng coordinates in R-CodePudding

My data set has 4 columns which are station_name, station_lat, station_lng, and count. This is the example of my data set.

start_stations <-
  data.frame(
    station = c("StreeterDr", "MichiganAve", "WellsSt"),
    lat = c(41.89228, 41.90096, 41.91213),
    lng = c(-87.61204,-87.62378,-87.63466),
    n = c(23000, 56780, 34520)
  )

I need to plot a map using these coordinates and color variations to stations (locations) according to its count and label each location using name and count. I tried this code, and an error occurred.

install.packages(c("leaflet", "sp")) 
library(leaflet)
library(sp)
install.packages("sf")
library(sf)

lon <- start_stations$lng
lat <- start_stations$lat
name <- start_stations$station
count <- start_stations$n
dfs <- as.data.frame(cbind(lon,lat,name,count))

dfs<- st_as_sf(dfs)

getColor <- function(dfs) {
  sapply(dfs$count, function(count) {
  if(count <= 20000) {
    "green"
  } else if(count <= 30000) {
    "orange"
  } else {
    "red"
  } })
}

icons <- awesomeIcons(
  icon = 'ios-close',
  iconColor = 'black',
  library = 'ion',
  markerColor = getColor(top100_start_station_cordinates)
)

leaflet(dfs) %>% addTiles() %>%
  addAwesomeMarkers(~lon, ~lat, icon=icons, popup = ~as.character(name), label=~as.character(count))

CodePudding user response：

You need to define the coords when using st_as_sf.

dfs <- sf::st_as_sf(dfs, coords = c("lon","lat"))

# But you might also want to go ahead and define the projection here too. 
# If so, then add in the crs argument.
# dfs <- sf::st_as_sf(dfs, coords = c("lon", "lat"), crs = 4326)

Output

Simple feature collection with 3 features and 2 fields
Geometry type: POINT
Dimension:     XY
Bounding box:  xmin: -87.63466 ymin: 41.89228 xmax: -87.61204 ymax: 41.91213
CRS:           NA
         name count                   geometry
1  StreeterDr 23000 POINT (-87.61204 41.89228)
2 MichiganAve 56780 POINT (-87.62378 41.90096)
3     WellsSt 34520 POINT (-87.63466 41.91213)

Then, you should be able to run your remaining code and get the leaflet output.