LeafLetMapExample

University of the West Indies Open Campus Sites.

set.seed(2017-08-16)
library (plyr)

# google mapping library
library(ggmap)

# leaflet library
library(leaflet)
# load base address data
addresses <- read.csv("~/Coursea/LeafLetExamples/uwiOCsites.csv",
                      stringsAsFactors = FALSE)

# get geocode informaton via the google api
geo_reply = suppressWarnings(
  geocode(addresses$Address, 
                    output="all",messaging = FALSE ,override_limit = TRUE))

# function to extract required geocode elements - lat, lng, addr, Country
get_coords <- function(x) {
  if(class(x)=="list") {
    list("lat" = x$results[[1]]$geometry$location$lat,
      "lng" = x$results[[1]]$geometry$location$lng,
      "adr" = x$results[[1]]$formatted_address,
      subset(ldply(x$results[[1]]$address_components, data.frame),types=="country",select=long_name))
      }
}

# extract geocode elements
geo_latlona <- sapply(geo_reply, get_coords) 

#convert list to dataframe
df <- ldply (geo_latlona, data.frame)

# The UWI Icon
uwiIcon <- makeIcon(
  iconUrl = "https://pbs.twimg.com/profile_images/476414443102818304/va0bNPKC.jpeg",
  iconWidth = 61*215/230, iconHeight = 61,
  iconAnchorX = 91*215/230/2, iconAnchorY = 35
  )

# build the leaflet map map
library(leaflet)
df[,1:2] %>%
  leaflet(width = "100%") %>% 
  addTiles() %>%
  addMarkers( popup = df$adr,clusterOptions = markerClusterOptions()) %>%
  addMarkers(
    icon = uwiIcon, popup = "<a href='http://www.open.uwi.edu/'>UWI Open Campus</a>",
    lng=-80.456554, lat=14.078039) %>%
addLabelOnlyMarkers(
  lng=-80.456554, lat=14.078039,
  label='University of the West Indies, Open Campus Sites',
                    labelOptions = labelOptions(noHide = T)) %>%
  addLabelOnlyMarkers(
    lng=-80.456554, lat=11.078039,
    label='Map Created on: 2017.8.16',
    labelOptions = labelOptions(noHide = T))