Grab lat / lon from an address using Google Maps

google_geocode.R

# Get a lat/lon value for each address
geocode.addr <- function(city, country) {
	geo.url <- "http://maps.googleapis.com/maps/api/geocode/json?address="
	geo.text <- getURL(paste(geo.url, URLencode(paste(city, country, collapse="+")), "&sensor=false", sep=""))
	geo.json <- fromJSON(geo.text)
	if(geo.json$status == "OK"){
		return(geo.json$results[[1]]$geometry$location)
	}
	else{
		if(geo.json$status == "OVER_QUERY_LIMIT") {
				stop("Hit rate limit")
		}
		else {
			return(c(NA, NA))
		}
	}
}