我已经在谷歌注册，以获得更多的驾驶时间距离请求。然而，谷歌并没有自动获得每天运行2500多个查询的"权限"。此外，mapdist()没有用于集成API键的参数。
我已经设法通过谷歌控制台获得了一个API密钥。
我试图修改原始代码添加关键字并更改行56、90&91如下：
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)
}
然而，我在运行mapdist（）时收到了以下错误消息：
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)
我觉得我必须在R上的代码中集成这个密钥，以便谷歌获得我的"许可"。一个朋友告诉我可以通过httr来完成，但我对此了解不多。我对编码真的不太了解，如果有任何帮助，我将不胜感激！
我已经编写了包googleway以访问谷歌地图API，您可以在其中指定您的代币密钥
For example
library(googleway)
key <- "your_api_key"
google_distance(origins = list("houston", "Dallas"),
destinations = list("waco, Texas", "San Antonio"),
key = key,
simplify = FALSE) ## use simplify = T to simplify to a data.frame
[1] "{"
[2] " "destination_addresses" : [ "Waco, TX, USA", "San Antonio, TX, USA" ],"
[3] " "origin_addresses" : [ "Houston, TX, USA", "Dallas, TX, USA" ],"
[4] " "rows" : ["
[5] " {"
[6] " "elements" : ["
[7] " {"
[8] " "distance" : {"
[9] " "text" : "299 km","
[10] " "value" : 298585"
[11] " },"
[12] " "duration" : {"
[13] " "text" : "2 hours 51 mins","
[14] " "value" : 10244"
[15] " },"
[16] " "duration_in_traffic" : {"
[17] " "text" : "2 hours 52 mins","
[18] " "value" : 10343"
[19] " },"
[20] " "status" : "OK""
[21] " },"
... etc
我修改了核心代码（在命令之前运行）如下：
#' Compute map distances using Google
#'
#' Compute map distances using Google Maps. Note that in most cases
#' by using this function you are agreeing to the Google Maps API
#' Terms of Service at https://developers.google.com/maps/terms.
#'
#' @param from name of origin addresses in a data frame (vector
#' accepted)
#' @param to name of destination addresses in a data frame (vector
#' accepted)
#' @param output amount of output
#' @param mode driving, bicycling, or walking
#' @param messaging turn messaging on/off
#' @param sensor whether or not the geocoding request comes from a
#' device with a location sensor
#' @param language language
#' @param override_limit override the current query count
#' (.GoogleDistQueryCount)
#' @return a data frame (output="simple") or all of the geocoded
#' information (output="all")
#' @author David Kahle email{david.kahle@@gmail.com}
#' @details if parameters from and to are specified as geographic
#' coordinates, they are reverse geocoded with revgeocode. note
#' that the google maps api limits to 2500 element queries a day.
#' @seealso
#' url{http://code.google.com/apis/maps/documentation/distancematrix/}
#'
#' @export
#' @examples
#'
#' dontrun{ online queries draw R CMD check times
#'
#' mapdist("waco, texas", "houston, texas")
#'
#' from <- c("houston, texas", "dallas")
#' to <- "waco, texas"
#' mapdist(from, to)
#' mapdist(from, to, mode = "bicycling")
#' mapdist(from, to, mode = "walking")
#'
#' from <- c("houston", "houston", "dallas")
#' to <- c("waco, texas", "san antonio", "houston")
#' mapdist(from, to)
#'
#'
#' # geographic coordinates are accepted as well
#' (wh <- as.numeric(geocode("the white house, dc")))
#' (lm <- as.numeric(geocode("lincoln memorial washington dc")))
#' mapdist(wh, lm, mode = "walking")
#' distQueryCheck()
#'
#' }
#'
mapdist <- function(from, to, mode = c("driving","walking","bicycling"),
output = c("simple","all"), messaging = FALSE, sensor = FALSE,
language = "en-EN", override_limit = FALSE, key)
{
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("https://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)
}
然后，我可以通过添加密钥名称"1234"来修改mapdist()命令，如下所示：
# create your own 'from' and 'to' variables
from <- drivetime$gp_postcode
to <- drivetime$h_postcode
result <- vector("list")
for (i in 1:nrow(drivetime)) { # could be 1:nrow(drivetime)
result[[i]] <- mapdist(from[i], to[i], mode = "driving", override_limit = TRUE, key="1234")
Sys.sleep(0.5)
}
results <- dput(result)
res_df <- do.call(rbind, results)
您可以在此处跟踪查询次数和计费