My first leaflet

We first create a leaflet object, and then add markers:

library(leaflet)

## Warning: package 'leaflet' was built under R version 3.3.3

my_map <- leaflet() %>%
  addTiles()

my_map <- my_map %>%
  addMarkers(lat=1.3521, lng=103.8198,
             popup="Singapore")
my_map

Mapping Clusters

df <- data.frame(lat=runif(100, min=1.33, max = 1.37 ),
                 lng=runif(100, min=103.5, max = 104 ))

df %>%
leaflet() %>%
addTiles() %>%  
addMarkers(clusterOptions = markerClusterOptions())