使用R中的URL_GT从Google趋势下载CSV

Question

我正在尝试模拟浏览器，以便从Google趋势下载数据。我正在使用的代码如下：

URL_GT=function(keyword="", country=NA, region=NA, year=NA, month=1, length=3){

  start="http://www.google.com/trends/trendsReport?hl=en-US&q="
  end="&cmpt=q&content=1&export=1"
  geo=""
  date=""

  #Geographic restrictions
  if(!is.na(country)) {
    geo="&geo="
    geo=paste(geo, country, sep="")
    if(!is.na(region)) geo=paste(geo, "-", region, sep="")
  }

  queries=keyword[1]
  if(length(keyword)>1) {
    for(i in 2:length(keyword)){
      queries=paste(queries, "%2C ", keyword[i], sep="")
    }
  }

  #Dates
  if(!is.na(year)){
    date="&date="
    date=paste(date, month, "%2F", year, "%20", length, "m", sep="")
  }

  URL=paste(start, queries, geo, date, end, sep="")
  URL <- gsub(" ", "%20", URL)
  return(URL)
}

downloadGT=function(URL, downloadDir){
  #Determine if download has been completed by comparing the number of files in the download directory to the starting number
  startingFiles=list.files(downloadDir)
  browseURL(URL)
  endingFiles=list.files(downloadDir)

  while(length(setdiff(endingFiles,startingFiles))==0) {
    Sys.sleep(3)
    endingFiles=list.files(downloadDir)
  }
  filePath=setdiff(endingFiles,startingFiles)
  return(filePath)
}

我遇到的问题是URL不再起作用。我正在尝试更新它，但是我不确定如何找到检索csv文件的链接。当我在此代码中使用URL时，它表示该页面不再可用。