[R] convert Splus mapproject() in R

Barry Rowlingson B.Rowlingson at lancaster.ac.uk
Mon Feb 24 17:02:10 CET 2003

Liaw, Andy wrote:
> That function does not seem to exist in Splus 6.1.2 release 2 for Linux.
> Could it be that it's written by someone locally, or it was in some add-on
> module?

Its part of the 'maps' library. Ray Brownrigg has ported it to R, but 
looking at the DESCRIPTION file tells me this:

Description: Display of maps.  The projection code found in the original
         S code is not included because of unclear licensing issues (and
         that code didn't work straight off anyway :-)).

  If the original poster is feeling brave, my Rmap library will do map 
projections using the PROJ4 library (so you'll have to install that 
first). Its in a very early state, and the current version wont read 
that format of map file (thing.G, thing.L, thing.N files) if thats what 
is being used.

  But it might be that all is needed is a project(xy) function, which my 
code does as a simple (~5 line) wrapper to the PROJ4 library.


  But be warned, its very very fragile and I cant help you if it fails.


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