Convenience function for looking up latitude/longitude coordinate information for a given location. Returns data as a special "coords" object, which is specifically designed to interact smoothly with other relevant package functions. NOTE: USE OF THIS FUNCTION REQUIRES A VALID GOOGLE MAPS API KEY.
Arguments
- address
Desired location typically in the form of place name, subregion, e.g., address = "lawrence, KS". Also accepts the name of countries, e.g., address = "usa", address = "brazil" or states, e.g., address = "missouri" or cities, e.g., address = "chicago". In most cases using only address should be sufficient.
- components
Unit of analysis for address e.g., components = "country:US". Potential components include postal_code, country, administrative_area, locality, route.
- apikey
A valid Google Maps API key. If NULL,
lookup_coords()will look for a relevant API key stored as an environment variable (e.g.,GOOGLE_MAPS_KEY).- ...
Additional arguments passed as parameters in the HTTP request
Details
Since Google Maps implemented stricter API requirements, sending
requests to Google's API isn't very convenient. To enable basic uses
without requiring a Google Maps API key, a number of the major cities
throughout the word and the following two larger locations are
baked into this function: 'world' and 'usa'. If 'world' is supplied then
a bounding box of maximum latitutde/longitude values, i.e.,
c(-180, -90, 180, 90), and a center point c(0, 0) are
returned. If 'usa' is supplied then estimates of the United States'
bounding box and mid-point are returned. To specify a city, provide the
city name followed by a space and then the US state abbreviation or
country name. To see a list of all included cities, enter
rtweet:::citycoords in the R console to see coordinates data.
See also
Other geo:
lat_lng()
Examples
if (FALSE) {
## get coordinates associated with the following addresses/components
sf <- lookup_coords("san francisco, CA", "country:US")
usa <- lookup_coords("usa")
lnd <- lookup_coords("london")
bz <- lookup_coords("brazil")
## pass a returned coords object to search_tweets
bztw <- search_tweets(geocode = bz)
## or stream tweets
ustw <- stream_tweets(usa, timeout = 10)
}