使用R和Google Map API获取两点之间的距离(lat,lon)

Question

我试图通过给出lat/lon来获得两点之间的行驶距离.我可以手动将它们放入谷歌地图并获得驾驶距离,但我想以编程方式完成所有这些操作.

我想JavaScript是最常用的语言.但是,我不知道JavaScript,我相当熟悉使用R.我更喜欢在R中这样做,因为我在R中进行所有数据分析.

我正在寻找沿着道路的距离而不是飞行距离.经过几个小时的尝试,我在R中编写了以下函数(这个和这一个帮助).你有没有更好的方法来获得这个功能或任何非常简单的距离？

library(XML)
latlon2ft <- function(origin,destination)
{

xml.url <- paste0('http://maps.googleapis.com/maps/api/distancematrix/xml?origins=',origin,'&destinations=',destination,'&mode=driving&sensor=false')

xmlfile <- xmlTreeParse(xml.url)
xmltop = xmlRoot(xmlfile)
distance <- xmltop[['row']][[1]][5][1][['distance']][['value']][[1]]
distance <- as.numeric(unclass(distance)[['value']])
ft <- distance*3.28084 # FROM METER TO FEET
return(ft)
}

latlon2ft(origin='37.193489,-121.07395',destination='37.151616,-121.046586')

结果= 17224.41

Answer 1

你需要RCurl或等同于此.

library(XML)
library(bitops)
library(RCurl)
latlon2ft <- function(origin,destination){
  xml.url <- paste0('http://maps.googleapis.com/maps/api/distancematrix/xml?origins=',origin,'&destinations=',destination,'&mode=driving&sensor=false')
  xmlfile <- xmlParse(getURL(xml.url))
  dist <- xmlValue(xmlChildren(xpathApply(xmlfile,"//distance")[[1]])$value)
  distance <- as.numeric(sub(" km","",dist))
  ft <- distance*3.28084 # FROM METER TO FEET
  return(ft)
}

latlon2ft(origin='37.193489,-121.07395',destination='37.151616,-121.046586')

结果:

[1] 17224.41

Answer 2

我编写该gmapsdistance程序包就是为了做到这一点。它在CRAN上可用。您可以通过以下方式使用该功能：

results = gmapsdistance(origin = "38.1621328+24.0029257",
                        destination = "37.9908372+23.7383394",
                        mode = "walking") results
# $Time
# [1] 30025
# 
# $Distance
# [1] 39507
# 
# $Status
# [1] "OK"

您还可以包括起点和终点的向量，并获得结果距离矩阵。它也支持路线，并且有很多选项：

results = gmapsdistance(origin = c("Washington+DC", "New+York+NY", "Seattle+WA", "Miami+FL"), 
                        destination = c("Los+Angeles+CA", "Austin+TX", "Chicago+IL", "Philadelphia+PA"), 
                        mode = "bicycling", 
                        departure = 1514742000)
results
# $Time
#              or Time.Los+Angeles+CA Time.Austin+TX Time.Chicago+IL Time.Philadelphia+PA
# 1 Washington+DC              856621         535146          247765                54430
# 2   New+York+NY              917486         596011          308630                32215
# 3    Seattle+WA              374692         678959          674989               956702
# 4      Miami+FL              829039         416667          452035               411283
# 
# $Distance
#              or Distance.Los+Angeles+CA Distance.Austin+TX Distance.Chicago+IL Distance.Philadelphia+PA
# 1 Washington+DC                 4567470            2838519             1303067                   266508
# 2   New+York+NY                 4855086            3126136             1590684                   160917
# 3    Seattle+WA                 1982354            3562970             3588297                  5051951
# 4      Miami+FL                 4559205            2279966             2381610                  2169382
# 
# $Status
#              or status.Los+Angeles+CA status.Austin+TX status.Chicago+IL status.Philadelphia+PA
# 1 Washington+DC                    OK               OK                OK                     OK
# 2   New+York+NY                    OK               OK                OK                     OK
# 3    Seattle+WA                    OK               OK                OK                     OK
# 4      Miami+FL                    OK               OK                OK                     OK