緯度/経度を取得するには、このようなものから始めます
各郵便番号の緯度/経度を取得する
library(XML)
school.postcodes <- c("KA12 6QE", "SW1A 0AA", "WC1X 9NT")
ll <- lapply(school.postcodes,
function(str){
u <- paste('http://maps.google.com/maps/api/geocode/xml?sensor=false&address=',str)
doc <- xmlTreeParse(u, useInternal=TRUE)
lat=xpathApply(doc,'/GeocodeResponse/result/geometry/location/lat',xmlValue)[[1]]
lng=xpathApply(doc,'/GeocodeResponse/result/geometry/location/lng',xmlValue)[[1]]
c(code = str,lat = lat, lng = lng)
})
# get long/lat for the students
ll.students <- lapply(student.data$post.codes,
function(str){
u <- paste('http://maps.google.com/maps/api/geocode/xml?sensor=false&address=',str)
doc <- xmlTreeParse(u, useInternal=TRUE)
lat=xpathApply(doc,'/GeocodeResponse/result/geometry/location/lat',xmlValue)[[1]]
lng=xpathApply(doc,'/GeocodeResponse/result/geometry/location/lng',xmlValue)[[1]]
c(code = str,lat = lat, lng = lng)
})
ll <- do.call(rbind,ll)
ll.students <- do.call(rbind,ll.students)
do.call(rbind,ll)
code lat lng
[1,] "KA12%206QE" "55.6188429" "-4.6766226"
[2,] "SW1A%200AA" "51.5004864" "-0.1254664"
[3,] "WC1X%209NT" "51.5287992" "-0.1181098"
距離行列を取得する
library(RJSONIO)
dist.list <- lapply(seq(nrow(ll)),
function(id){
url <- paste("http://maps.googleapis.com/maps/api/distancematrix/json?origins=",
ll[id,2],",",ll[id,3],
"&destinations=",
paste( ll.students[,2],ll.students[,3],sep=',',collapse='|'),
"&sensor=false",sep ='')
res <- fromJSON(url)
hh <- sapply(res$rows[[1]]$elements,function(dest){
c(distance= as.numeric(dest$distance$value),
duration = dest$duration$text)
})
hh <- rbind(hh,destination = ll.students[,1])
})
names(dist.list) <- ll[,1]
dist.list
$`SL4 6DW`
[,1] [,2] [,3]
distance "664698" "36583" "41967"
duration "6 hours 30 mins" "43 mins" "49 mins"
destination "1" "2" "3"
$`SW13 9JT`
[,1] [,2] [,3]
distance "682210" "9476" "13125"
duration "6 hours 39 mins" "22 mins" "27 mins"
destination "1" "2" "3"