JSON: Google Map Distance Matrix Data in R “How to download JSON data into R?”

问题

I am trying to get the data from the Google Map API Distance Matrix to R. I am trying to get the JSON data into R. How to download JSON data into R, so I will be able parse later?

require(rjson)
url <- "https://maps.googleapis.com/maps/api/distancematrix/jsonunits=imperial&origins=19+East+34th+Street+NewYork+NY+10016&destinations=40.5177433,-74.2749576&mode=transit&language=fr-FR&key=API_KEY_HERE"
raw.data <- readLines(url, warn = "F")
rd <- fromJSON(raw.data)

I am getting this error:

Error in fromJSON(raw.data) : unexpected character '<'

Thank you for the help

回答1:

It just so happens I've written a package, googleway that can help:

library(googleway)

google_distance(origins = "19 East 34th Street NewYork NY 10016",
                destinations = list(c(40.5177433,-74.2749576)),
                key = key,
                mode = "transit",
                language = "fr")

$destination_addresses
[1] "350-356 Lawrie St, Perth Amboy, NJ 08861, États-Unis"

$origin_addresses
[1] "19 E 34th St, New York, NY 10016, États-Unis"

$rows
elements
1 51,3 km, 51305, 1 heure 27 min, 5249, OK

$status
[1] "OK"

Similarly, set simplify = FALSE to get the raw json

google_distance(origins = "19 East 34th Street NewYork NY 10016",
                destinations = list(c(40.5177433,-74.2749576)),
                key = key,
                mode = "transit",
                language = "fr",
                simplify = FALSE)


[1] "{"                                                                                           
[2] "   \"destination_addresses\" : [ \"350-356 Lawrie St, Perth Amboy, NJ 08861, États-Unis\" ],"
[3] "   \"origin_addresses\" : [ \"19 E 34th St, New York, NY 10016, États-Unis\" ],"             
[4] "   \"rows\" : ["                                                                             
[5] "      {"                                                                                     
[6] "         \"elements\" : ["                                                                   
[7] "            {"                                                                               
[8] "               \"distance\" : {"                                                             
[9] "                  \"text\" : \"51,3 km\","                                                   
[10] "                  \"value\" : 51305"                                                         
[11] "               },"                                                                           
[12] "               \"duration\" : {"                                                             
[13] "                  \"text\" : \"1 heure 27 min\","                                            
[14] "                  \"value\" : 5249"                                                          
[15] "               },"                                                                           
[16] "               \"status\" : \"OK\""                                                          
[17] "            }"                                                                               
[18] "         ]"                                                                                  
[19] "      }"                                                                                     
[20] "   ],"                                                                                       
[21] "   \"status\" : \"OK\""                                                                      
[22] "}"

(where simplify == TRUE uses jsonlite::fromJSON)

回答2:

I figure out how to do it by JSONLite. I was using the native "fromJSON" of R and that was causing problems.

rd <-jsonlite::fromJSON("Google_API_CALL_IN_HERE", simplifyDataFrame = TRUE)

来源：https://stackoverflow.com/questions/37553071/json-google-map-distance-matrix-data-in-r-how-to-download-json-data-into-r

标签

json

google-maps

google-distancematrix-api