R/geocodeAddress.R

In walshc/GoogleMapsAPI: GoogleMapsAPI

geocodeAddress <- function(address, result = 1, pause.time = 0.02) {
  if (grepl("&", address)) {
    address <- gsub("&", "", address)
  }
  address <- iconv(address, to = "ASCII//TRANSLIT")
  root  <- "http://maps.google.com/maps/api/geocode/json?address="
  url <- URLencode(paste(root, address, "&sensor=false", sep = ""))
  x <- RJSONIO::fromJSON(url, simplify = FALSE)
  out <- list()
  if (x$status == "OK") {
    r <- result
    # Centroid coordinates of first search result:
    out$crd <- c(x$results[[r]]$geometry$location$lng,
                 x$results[[r]]$geometry$location$lat)
    names(out$crd) <- c("lon", "lat")

    # Data.frame of address components for checking:
    name <- do.call(rbind, lapply(x$results[[r]]$address_components, function(y)
                                  c(y$long_name, y$short_name)))
    type <- sapply(x$results[[r]]$address_components, function(y)
                   paste(y$types, collapse=", "))
    out$address <- data.frame(cbind(name, type))
    out$address[] <- lapply(out$address, as.character)
    names(out$address) <- c("long_name", "short_name", "type")
  } else {
    # If no result is found:
    out <- list(crd = c(lon = NA, lat = NA),
                address = data.frame(long_name = NA,
                                     short_name = NA,
                                     type = NA))
    warning("Request Status: ", x$status)
  }
  Sys.sleep(pause.time)
  return(out)
}