R/reverseGeocode.R

In walshc/GoogleMapsAPI: GoogleMapsAPI

reverseGeocode <- function(crd, result = 1, pause.time = 0.02) {
  r <- result
  url <- "http://maps.google.com/maps/api/geocode/json?latlng="
  url <- paste0(url, crd[2], "+", crd[1], "&sensor=false")
  doc <- URLencode(url)
  x <- RJSONIO::fromJSON(doc, simplify = FALSE)
  if (x$status == "OK") {
    out <- list()
    out$address <- x$results[[r]]$formatted_address

    # 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.components <- data.frame(cbind(name, type))
    out$address.components[] <- lapply(out$address.components, as.character)
    names(out$address.components) <- c("long_name", "short_name", "type")
    return(out)
  } else {
    out <- list(address = NA, address.components  = data.frame(long_name = NA,
                                                               short_name = NA,
                                                               type = NA))
    warning("Request Status: ", x$status)
  }
  Sys.sleep(pause.time)
}