Using Shapes file to update the "world" map
On Tue, 28 Jul 2009, Sean Carmody wrote:
I recently began playing around with the maps package, but am definitely a novice when it comes to geographic data. While the map function is very easy to use, the map data is out of date, particularly when it comes to former Soviet Union countries. I have tried to search the archives to work out how to update the file, but have become rather stuck. I found these instructions: http://spatial.nhh.no/R/etc/world_map_intro.html but could not quite follow them.
Please use the wrld_simpl data set bundled with the maptools package, and use your choice of its attributes (see names(wrld_simpl) - probably ISO3) to key to your data. See spCbind() methods in maptools for control in assigning, and review the sp SpatialPolygonDataFrame class used. Roger
They did, however, point me to this site http://thematicmapping.org/downloads/world_borders.php which has a more up to date file of country borders. After downloading this file, I managed to read in the shape file using read.shape and then plotted the result using Map2poly and this confirmed that the data was good. However, the read.shape gave me various error messages about extra data in the file and, although I could plot the whole world, I don't know how to identify individual countries. Ideally, I would like to take the downloaded border file data and convert into file formats that the map function can understand. Any suggestions as to how to do this or any alternative approaches would be greatly appreciated. To get an idea of what I am trying to do, this post has examples using the old map data: http://www.stubbornmule.net/2009/07/arms-trade/
Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no