Ich habe mich bei Google registriert, um mehr Anfragen zu Fahrzeitentfernungen zu erhalten. Google nimmt diese "Erlaubnis" jedoch nicht automatisch entgegen, um mehr als 2500 Abfragen pro Tag auszuführen. Zusätzlichmapdist() hat kein Argument, um einen API-Schlüssel zu integrieren.

Ich habe es geschafft, einen API-Schlüssel über die Google-Konsole abzurufen.

Ich habe versucht, den Rohcode zu ändern, indem ich den Schlüssel hinzufügte und die Zeilen 56, 90 und 91 wie folgt änderte:

    mapdist <- function(from, to, mode = c("driving","walking","bicycling"),
  output = c("simple","all"), messaging = FALSE, sensor = FALSE,
  language = "en-EN", override_limit = FALSE, key = "XXXX")
{

  message("by using this function you are agreeing to the terms at :")
  message("http://code.google.com/apis/maps/documentation/distancematrix/\n")

  # check parameters
  if(is.numeric(from) && length(from) == 2) from <- revgeocode(from)
  stopifnot(is.character(from))
  if(is.numeric(to) && length(to) == 2) to <- revgeocode(to)
  stopifnot(is.character(to))
  from_to_df <- data.frame(from = from, to = to, stringsAsFactors = FALSE)
  origins <- from_to_df$from
  destinations <- from_to_df$to # this ensures # from = # to
  mode <- match.arg(mode)
  output <- match.arg(output)
  stopifnot(is.logical(messaging))
  stopifnot(is.logical(sensor))


  getdists <- function(df){

    # format url
    origin <- df$from[1]
    origin <- gsub(",", "", origin)
    origin <- gsub(" ", "+", origin)
    origin <- paste("origins=", origin, sep = "")
    destinations <- df$to
    destinations <- gsub(",", "", destinations)
    destinations <- gsub(" ", "+", destinations)
    destinations <- paste("destinations=", paste(destinations, collapse = "|"), sep = "")
    mode4url <- paste("mode=", mode, sep = "")
    lang4url <- paste("language=", language, sep = "")
    sensor4url <- paste("sensor=", tolower(as.character(sensor)), sep = "")
    keyUrl <- paste("key=", key, sep = "")
    posturl <- paste(origin, destinations, mode4url, sensor4url, keyUrl, sep = "&")
    url_string <- paste("http://maps.googleapis.com/maps/api/distancematrix/json?",
      posturl, sep = "")
    url_string <- URLencode(url_string)


    # check if query is too long
    if(nchar(url_string) >= 2048){
      n <- nrow(df)
      half_df <- floor(n/2)
      return(
        rbind(
          getdists(df[half_df,]),
          getdists(df[(half_df+1):n,])
        )
      )
    }

    # check/update google query limit
    check_dist_query_limit(url_string, elems = nrow(df),
      override = override_limit, messaging = messaging)


    # distance lookup
    if(messaging) message("trying url ", url_string)
    connect <- url(url_string)
    tree <- fromJSON(paste(readLines(connect), collapse = ""))
    close(connect)

    # message user
    message(paste0("Information from URL : ", url_string))

    # label destinations - first check if all were found
    if(length(df$to) != length(tree$destination_addresses)){
      message("matching was not perfect, returning what was found.")
      names( tree$rows[[c(1,1)]] ) <- tree$destination_addresses
      output <<- "all"
      # stringdist::amatch(df$to, tree$destination_addresses, maxDist = 10)
    } else {
      names( tree$rows[[c(1,1)]] ) <- df$to
    }

    # return
    tree$rows[[c(1,1)]]
  }

  out <- dlply(from_to_df, "from", getdists)

  # return all
  if(output == "all") return(out)



  # format output
  out <-
    ldply(out, function(oneFromList){
      ldply(oneFromList, function(oneToList){
        data.frame(
          m = oneToList$distance$value,
          km = oneToList$distance$value/1000,
          miles = 0.0006214 * oneToList$distance$value,
          seconds = oneToList$duration$value,
          minutes = oneToList$duration$value / 60,
          hours = oneToList$duration$value / 3600
        )
      })
    })

  names(out) <- c("from", "to", names(out)[3:ncol(out)])

  # "simple" return
  suppressMessages(join(from_to_df, out))
}




check_dist_query_limit <- function(url_string, elems, override, messaging){
  .GoogleDistQueryCount <- NULL; rm(.GoogleDistQueryCount); # R CMD check trick

  if(exists(".GoogleDistQueryCount", .GlobalEnv)){

    .GoogleDistQueryCount <<-
      subset(.GoogleDistQueryCount, time >= Sys.time() - 24*60*60)

    # 2500 per 24 hours
    if(sum(.GoogleDistQueryCount$elements) + elems > 2500){
      message("query max exceeded, see ?mapdist.  current total = ",
        sum(.GoogleDistQueryCount$elements))
      if(!override) stop("google query limit exceeded.", call. = FALSE)
    }

    # 100 per 10 seconds
    if(with(.GoogleDistQueryCount,
      sum(elements[time >= Sys.time() - 10]) + elems > 100
    )){
      if(messaging) message("waiting 10 seconds for another 100 queries...", appendLF=F)
      Sys.sleep(10) # can do better
      if(messaging) message(" done")
    }

    # append to .GoogleDistQueryCount
    .GoogleDistQueryCount <<- rbind(.GoogleDistQueryCount,
      data.frame(time = Sys.time(),  url = url_string,
        elements = elems, stringsAsFactors = FALSE)
    )


  } else {

    .GoogleDistQueryCount <<-
      data.frame(time = Sys.time(),  url = url_string,
        elements = elems, stringsAsFactors = FALSE)

  }
}



#' Check Google Maps Distance Matrix API query limit
#'
#' Check Google Maps Distance Matrix API query limit
#'
#' @return a data frame
#' @author David Kahle \email{david.kahle@@gmail.com}
#' @seealso \url{http://code.google.com/apis/maps/documentation/distancematrix/}
#' @export
#' @examples
#' distQueryCheck()
distQueryCheck <- function(){
  .GoogleDistQueryCount <- NULL; rm(.GoogleDistQueryCount); # R CMD check trick
  if(exists(".GoogleDistQueryCount", .GlobalEnv)){
    remaining <- 2500-sum(
      subset(.GoogleDistQueryCount, time >= Sys.time() - 24*60*60)$elements
      )
    message(remaining, " distance queries remaining.")
  } else {
    remaining <- 2500
    message(remaining, " distance queries remaining.")
  }
  invisible(remaining)
}

Aber ich habe beim Ausführen von mapdist () die folgende Fehlermeldung erhalten:

by using this function you are agreeing to the terms at :
http://code.google.com/apis/maps/documentation/distancematrix/

Information from URL : http://maps.googleapis.com/maps/api/distancematrix/json?origins=NG17+7LG&destinations=CV2+2DX&mode=driving&sensor=false&key=AIzaSyBQN9Dvgfw3bXpWj_-ddluungZcDv8Y4rg
matching was not perfect, returning what was found.
Error in `*tmp*`[[c(1, 1)]] : no such index at level 1
Called from: .fun(piece, ...)
Browse[1]> results <- dput(result)
list()
Browse[1]> res_df <- do.call(rbind, results)

Ich habe das Gefühl, dass ich diesen Schlüssel in meinen Code auf R integrieren muss, damit Google meine "Erlaubnis" abholt. Mir wurde von einem Freund gesagt, dass ich es durch @ tun könnthttr aber ich weiß nicht viel darüber. Ich weiß wirklich nicht viel über das Programmieren und würde mich über jede Hilfe freuen!