Geocode and reverse geocode your data using, R, JSON and Google Maps’ Geocoding API

To geocode and reverse geocode my data, I use Google’s Geocoding service which returns the geocoded data in a JSON. I will recommend that you register with Google Maps API and get a key if you have large amount of data and would do repeated geo coding.

Geocode:

getGeoCode <- function(gcStr)  {
  library(“RJSONIO”) #Load Library
  gcStr <- gsub(' ','%20',gcStr) #Encode URL Parameters
 #Open Connection
 connectStr <- paste('http://maps.google.com/maps/api/geocode/json?sensor=false&address=',gcStr, sep="") 
  con <- url(connectStr)
  data.json <- fromJSON(paste(readLines(con), collapse=""))
  close(con)
  #Flatten the received JSON
  data.json <- unlist(data.json)
  if(data.json[“status”]==”OK”)   {
    lat <- data.json["results.geometry.location.lat"]
    lng <- data.json["results.geometry.location.lng"]
    gcodes <- c(lat, lng)
    names(gcodes) <- c("Lat", "Lng")
    return (gcodes)
  }
}
geoCodes <- getGeoCode("Palo Alto,California")
> geoCodes
           Lat            Lng 
  “37.4418834” “-122.1430195” 

Reverse Geocode:
reverseGeoCode <- function(latlng) {
latlngStr <-  gsub(' ','%20', paste(latlng, collapse=","))#Collapse and Encode URL Parameters
  library(“RJSONIO”) #Load Library
  #Open Connection
  connectStr <- paste('http://maps.google.com/maps/api/geocode/json?sensor=false&latlng=',latlngStr, sep="")
  con <- url(connectStr)
  data.json <- fromJSON(paste(readLines(con), collapse=""))
  close(con)
  #Flatten the received JSON
  data.json <- unlist(data.json)
  if(data.json[“status”]==”OK”)
    address <- data.json["results.formatted_address"]
  return (address)
}
address <- reverseGeoCode(c(37.4418834, -122.1430195))
> address
                    results.formatted_address 
“668 Coleridge Ave, Palo Alto, CA 94301, USA” 

 Happy Coding!