reading address and lat,long from xml_node in R (mapsapi package) - r

Question

I'm trying to get informations from an address over the package mapsapi in R.
So my code looks like follows:
library(mapsapi)
library(XML)
library(RCurl)
string <- "Pariser Platz 1, 10117 Berlin"
test <- mp_geocode(string)
xml <- xml_child(test[[string]],2)
xml
Now I'm getting this kind of xml file:
{xml_node}
<result>
[1] <type>street_address</type>
[2] <formatted_address>Pariser Platz 1, 10117 Berlin, Germany</formatted_address>
[3] <address_component>\n <long_name>1</long_name>\n <short_name>1</short_name>\n <type>street_number</type>\n</address_component>
[4] <address_component>\n <long_name>Pariser Platz</long_name>\n <short_name>Pariser Platz</short_name>\n <type>route</type>\n</address_component>
[5] <address_component>\n <long_name>Mitte</long_name>\n <short_name>Mitte</short_name>\n <type>political</type>\n <type>sublocality</type>\n <type>sublocality_level_1</type>\n</address_component>
[6] <address_component>\n <long_name>Berlin</long_name>\n <short_name>Berlin</short_name>\n <type>locality</type>\n <type>political</type>\n</address_component>
[7] <address_component>\n <long_name>Berlin</long_name>\n <short_name>Berlin</short_name>\n <type>administrative_area_level_1</type>\n <type>political</type>\n</address_component>
[8] <address_component>\n <long_name>Germany</long_name>\n <short_name>DE</short_name>\n <type>country</type>\n <type>political</type>\n</address_component>
[9] <address_component>\n <long_name>10117</long_name>\n <short_name>10117</short_name>\n <type>postal_code</type>\n</address_component>
[10] <geometry>\n <location>\n <lat>52.5160964</lat>\n <lng>13.3779369</lng>\n </location>\n <location_type>ROOFTOP</location_type>\n <viewport>\n <southwest>\n <lat>52.5147474</lat>\n <lng>13.37658 ...
[11] <place_id>ChIJnYvtVcZRqEcRl6Kftq66b6Y</place_id>
So how can I export the street number, address, city, zip, lat and long out of this xml into decent variables?
Thanks for your help!
regards

Answer 1

I've made accessing this type of information easy in my googleway package
library(googleway)
## you're using Google's API, and they require you to have an API key
## so you'll need to get one
set_key("GOOGLE_API_KEY")
## perform query
res <- google_geocode("Pariser Platz 1, 10117 Berlin")
With the res result you can use geocode_coordinates() to extract the coordinates, and geocode_address_components() to get the street number
## coordinates
geocode_coordinates(res)
# lat lng
# 1 52.5161 13.37794
geocode_address_components(res)
# long_name short_name types
# 1 1 1 street_number
# 2 Pariser Platz Pariser Platz route
# 3 Mitte Mitte political, sublocality, sublocality_level_1
# 4 Berlin Berlin locality, political
# 5 Berlin Berlin administrative_area_level_1, political
# 6 Germany DE country, political
# 7 10117 10117 postal_code
You can look at str(res) to see the full list of items returned from Google's API

Answer 2

Alternatively, you can also use ggmap::geocode():
> library(ggmap)
> geocode(location = "Pariser Platz 1, 10117 Berlin", output = 'latlon' )
Information from URL : http://maps.googleapis.com/maps/api/geocode/json?address=Pariser%20Platz%201,%2010117%20Berlin&sensor=false
lon lat
1 13.37794 52.5161
Changing the output parameter can give you a very detailed list output (if required):
> geocode(location = "Pariser Platz 1, 10117 Berlin", output = 'all' )
Information from URL : http://maps.googleapis.com/maps/api/geocode/json?address=Pariser%20Platz%201,%2010117%20Berlin&sensor=false
$results
$results[[1]]
$results[[1]]$address_components
$results[[1]]$address_components[[1]]
$results[[1]]$address_components[[1]]$long_name
[1] "1"
$results[[1]]$address_components[[1]]$short_name
[1] "1"
$results[[1]]$address_components[[1]]$types
[1] "street_number"
$results[[1]]$address_components[[2]]
$results[[1]]$address_components[[2]]$long_name
[1] "Pariser Platz"
$results[[1]]$address_components[[2]]$short_name
[1] "Pariser Platz"
$results[[1]]$address_components[[2]]$types
[1] "route"
$results[[1]]$address_components[[3]]
$results[[1]]$address_components[[3]]$long_name
[1] "Mitte"
$results[[1]]$address_components[[3]]$short_name
[1] "Mitte"
$results[[1]]$address_components[[3]]$types
[1] "political" "sublocality" "sublocality_level_1"
$results[[1]]$address_components[[4]]
$results[[1]]$address_components[[4]]$long_name
[1] "Berlin"
$results[[1]]$address_components[[4]]$short_name
[1] "Berlin"
$results[[1]]$address_components[[4]]$types
[1] "locality" "political"
$results[[1]]$address_components[[5]]
$results[[1]]$address_components[[5]]$long_name
[1] "Berlin"
$results[[1]]$address_components[[5]]$short_name
[1] "Berlin"
$results[[1]]$address_components[[5]]$types
[1] "administrative_area_level_1" "political"
$results[[1]]$address_components[[6]]
$results[[1]]$address_components[[6]]$long_name
[1] "Germany"
$results[[1]]$address_components[[6]]$short_name
[1] "DE"
$results[[1]]$address_components[[6]]$types
[1] "country" "political"
$results[[1]]$address_components[[7]]
$results[[1]]$address_components[[7]]$long_name
[1] "10117"
$results[[1]]$address_components[[7]]$short_name
[1] "10117"
$results[[1]]$address_components[[7]]$types
[1] "postal_code"
$results[[1]]$formatted_address
[1] "Pariser Platz 1, 10117 Berlin, Germany"
$results[[1]]$geometry
$results[[1]]$geometry$location
$results[[1]]$geometry$location$lat
[1] 52.5161
$results[[1]]$geometry$location$lng
[1] 13.37794
$results[[1]]$geometry$location_type
[1] "ROOFTOP"
$results[[1]]$geometry$viewport
$results[[1]]$geometry$viewport$northeast
$results[[1]]$geometry$viewport$northeast$lat
[1] 52.51745
$results[[1]]$geometry$viewport$northeast$lng
[1] 13.37929
$results[[1]]$geometry$viewport$southwest
$results[[1]]$geometry$viewport$southwest$lat
[1] 52.51475
$results[[1]]$geometry$viewport$southwest$lng
[1] 13.37659
$results[[1]]$place_id
[1] "ChIJnYvtVcZRqEcRl6Kftq66b6Y"
$results[[1]]$types
[1] "street_address"
$status
[1] "OK"
You can find more info in the function help section.
Sometimes the call may fail with the following message:
Warning message:
geocode failed with status OVER_QUERY_LIMIT, location = "Pariser Platz 1, 10117 Berlin"
Generally if you try after a few seconds it works fine. You can always check the remaining queries left in your quota with geocodeQueryCheck:
> geocodeQueryCheck()
2490 geocoding queries remaining.