Tuesday, January 24, 2012

Geocode your data using, R, JSON and Google Maps' Geocoding APIs

Over the last year and half, I have faced numerous challenges with geocoding the data that I have used to showcase my passion for location analytics.  In 2012, I decided to take thing in my control and turned to R.  Here, I am sharing a simple R script that I wrote to geo-code my data whenever I needed it, even BIG Data.

To 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.

Here is function that can be called repeatedly by other functions:

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=""))
#Flatten the received JSON
  data.json <- unlist(data.json)
  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)

Let's put this function to test:
geoCodes <- getGeoCode("Palo Alto,California")

> geoCodes
           Lat            Lng 
  "37.4418834" "-122.1430195" 

You can run this on the entire column of a data frame or a data table:

Here  is my sample data frame with three columns - Opposition, Ground.Country and Toss. Two of the columns, you guessed it right, need geocoding.

> head(shortDS,10)
     Opposition              Ground.Country Toss
1      Pakistan            Karachi,Pakistan  won
2      Pakistan         Faisalabad,Pakistan lost
3      Pakistan             Lahore,Pakistan  won
4      Pakistan            Sialkot,Pakistan lost
5   New Zealand    Christchurch,New Zealand lost
6   New Zealand          Napier,New Zealand  won
7   New Zealand        Auckland,New Zealand  won
8       England              Lord's,England  won
9       England          Manchester,England lost
10      England            The Oval,England  won

To geo code this, here is a simple one liner I execute:

shortDS <- with(shortDS, data.frame(Opposition, Ground.Country, Toss,
                  laply(Ground.Country, function(val){getGeoCode(val)})))

> head(shortDS, 10)
    Opposition           Ground.Country Toss  Ground.Lat  Ground.Lng
1     Pakistan         Karachi,Pakistan  won   24.893379   67.028061
2     Pakistan      Faisalabad,Pakistan lost   31.408951   73.083458
3     Pakistan          Lahore,Pakistan  won    31.54505   74.340683
4     Pakistan         Sialkot,Pakistan lost  32.4972222  74.5361111
5  New Zealand Christchurch,New Zealand lost -43.5320544 172.6362254
6  New Zealand       Napier,New Zealand  won -39.4928444 176.9120178
7  New Zealand     Auckland,New Zealand  won -36.8484597 174.7633315
8      England           Lord's,England  won     51.5294     -0.1727
9      England       Manchester,England lost   53.479251   -2.247926
10     England         The Oval,England  won   51.369037   -2.378269

Happy Coding!


  1. Thanks for this great tool. Any idea why it returns a bunch of (but not all) NAs?

    1. google only allows 10 requests per second.

  2. Hi Dave, Where can I specify the API key?

  3. Can anyone here please explain about geocode and the use of it?

  4. HP Printer Support
    HP Printer Support Phone Number
    HP Printer Support Telephone Number
    HP Printer Support Contact Number
    HP Printer Support Toll Free Number
    HP Printer Support Online
    HP Printer Support Wireless
    HP Printer Support Telephone
    HP Printer Support Help
    HP Printer Support Helpline
    HP Printer Support Number usa
    HP Printer Support Line
    HP Printer Support Customer Service Number
    HP Printer Support usa
    Canon Printer Support Phone Number
    Canon Printer Support Number
    Canon printer technical Support
    Canon Printer Support usa
    Canon Printer Support Help
    Canon Printer Support Online
    Canon printer Support Telephone Number
    Canon printer Customer Support Phone Number
    Linksys Support
    Linksys Support Number
    Linksys Customer Support Number
    Linksys Support site
    Linksys Support Phone
    Linksys Support Chat
    Linksys Support Line
    Linksys Support Online
    Linksys Support website
    Linksys Support Number usa
    Pogo Game not loading
    Pogo Games Phone Number
    Pogo Game Customer toll free Number
    Pogo Game won't load
    Pogo Game Customer care Number
    Pogo Games contact us
    Pogo Games Helpline
    Pogo Games java problems
    Pogo Game Support
    Pogo Games Support Phone Number
    Pogo Game Support Number
    Pogo Games Customer Support
    Pogo Game tech Support Phone Number
    Pogo Games technical Support
    Pogo Games technical Support Phone Number

  5. Delta is an American airline major company, headquarters in Atlanta, Georgia and operates over 5400 flights every day. Delta operates with domestic and international flights in 52 countries include 325 destinations. Travelers may choose different cabin option as per their needs and capabilities like Delta One, Premium Select, First Class, Delta Comfort+, Main Cabin, and Basic Economy. Delta Airlines Reservation Phone Number will help you to plan your vacation and trips. You may dial Delta Airlines Phone Number to know your flight status, changes in your flight, upgrade your seats. A team of travel advisor is ready to listen to you and make your fly easy.

  6. HP Printer Support can offer a live professional who can help in a wide range of printer related issues.
    HP Printer Support Phone Number

  7. Within no time you will get the response from our experts with whom you can discuss the issues to get the solution. Our experts will provide you the user-friendly support on the chat to resolve the issues effectively from its main cause. Problems like installation issues, drivers update, and all other issues can be resolved through the Epson Printer Technical Support Number.

  8. Here for how to connect Epson wireless printer to Wifi? Solution for wireless printer on your WLAN network call Epson support number +1-800-436-0509 toll free, Epson Wireless Printer Setup
    How to connect Epson wireless printer to Wifi