[R] shapefiles manipulations ??

[Roger Bivand]

On Fri, 9 Sep 2005, justin bem wrote:

> cheers ,
>  I need help in shapefile manipulations. I have two shapefiles of my
> country Cameroon. The first contain 10 provinces and each province
> contains a certain number of administratives units. I dont have ESRI Arc
> view. I want to add a admistrative unit of the center province to the
> map with 10 province.
>  
> Is it possible to to take a peace of shapefile and combining it to another ?

In principle, yes. There are two R packages (maptools and shapefiles) that 
read and write shapefiles, and the newly released combination of maptools 
and the sp package should be able to handle this.

Since sp has objects defined down to the simple polygons, extracting a 
subset from one map and inserting it into another should not be too 
difficult.

The specific difficulty will be both to add the administrative unit, and 
to adjust the borders of the province that it belongs to. I suggest 
following this up on the R-sig-geo list; if you can make your shapefiles 
available (perhaps on a website), together with details of which 
administrative unit needs to be inserted, help should be forthcoming.

>  
> Thanks !
> 

-- 
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