Identifying country from latitude and longitude

[Thiago Soares]

Hi,

I am trying to identify the country from a latitude and longitude in Stata.
I tried to install the package geocode3, which apparently did the job.
Unfortunately it seems to be unavailable.
Does anyone know any alternatives?

Thanks in advance,
Thiago

[Robert Picard]

You can use geoinpoly (from SSC) to identify in which country each point (lat,lon) is located. You will need a suitable shapefile of the world. You can get such a shapefile by downloading the ancillary datasets of the geo2xy (from SSC) package to Stata's current directory using:

net get geo2xy, from("http://fmwww.bc.edu/repec/bocode/g")

Here's a quick example that locates the country for the following universities:

* Example generated by -dataex-. To install: ssc install dataex
clear
input str10 university double(lat lon)
"U of M"     42.276933 -83.738204
"MIT"        42.359758 -71.092064
"Sorbonne"   48.848527   2.343494
"Pompeu Fab" 41.378946   2.179807
end

geoinpoly lat lon using "geo2xy_world_coor.dta"

merge m:1 _ID using "geo2xy_world_data.dta", ///
    keep(master match) keepusing(geounit) nogen

list

and the results

. list

     +----------------------------------------------------------------------+
     | university         lat          lon   _ID                    geounit |
     |----------------------------------------------------------------------|
  1. | Pompeu Fab   41.378946     2.179807    50                      Spain |
  2. |   Sorbonne   48.848527     2.343494    56                     France |
  3. |        MIT   42.359758   -71.092064   169   United States of America |
  4. |     U of M   42.276933   -83.738204   169   United States of America |
     +----------------------------------------------------------------------+

.

[Thiago Soares]

Thank you for your answer, it works perfectly!