How to get the longitude and latitude coordinates from a city name and country in R?

With the following code I have successfully solved the problem.

library(RJSONIO)nrow <- nrow(test)counter <- 1test$lon[counter] <- 0test$lat[counter] <- 0while (counter <= nrow){  CityName <- gsub(' ','%20',test$CityLong[counter]) #remove space for URLs  CountryCode <- test$Country[counter]  url <- paste(    "http://nominatim.openstreetmap.org/search?city="    , CityName    , "&countrycodes="    , CountryCode    , "&limit=9&format=json"    , sep="")  x <- fromJSON(url)  if(is.vector(x)){    test$lon[counter] <- x[[1]]$lon    test$lat[counter] <- x[[1]]$lat      }  counter <- counter + 1}

As this is calling an external service (openstreetmaps.org) it can take a while for larger datasets. However, you probably only do this once in a while when new cities have been added to the list.

A few other options for you.

ggmaps

ggmaps has a function geocode which uses Google Maps to geocode. This limits you to 2,500 per day.

taRifx.geo

taRifx.geo's latest version has a geocode function which uses either Google or Bing Maps to geocode. The Bing version requires you to use a (free) Bing account, but in return you can geocode way more entries. Features in this version:

• Service choice (Bing and Google Maps both supported)
• Log-in support (particularly for Bing, which requires an account key but in exchange allows for an order of magnitude more daily requests)
• Geocode a whole data.frame at a time, including some time-savers like ignoring any rows which have already been geocoded
• Robust batch geocoding (so that any error does not cause the whole data.frame's worth of geocoding to be lost, for bigger jobs)
• Route finding (travel times from point A to point B)

Try this I think it will better solution for this problem

> library(ggmap) Loading required package: ggplot2Google Maps API Terms of Service: http://developers.google.com/maps/terms.Please cite ggmap if you use it: see citation('ggmap') for details.#Now you can give city name or country name individually> geocode("hamburg")Information from URL : http://maps.googleapis.com/maps/api/geocode/json?address=hamburg&sensor=false       lon      lat1 9.993682 53.55108geocode("amsterdam")Information from URL : http://maps.googleapis.com/maps/api/geocode/json?address=amsterdam&sensor=false       lon      lat1 4.895168 52.37022> geocode("new york")Information from URL : http://maps.googleapis.com/maps/api/geocode/json?address=new+york&sensor=false        lon      lat1 -74.00594 40.71278