[R-sig-Geo] polygon buffers?

[Roger Bivand]

On Sun, 2 Sep 2007, Peter Adler wrote:

> Dear R gurus,
>
> I am very excited about all the spatials tools in R because they have
> almost liberated me from ESRI products. One of the last things I have
> yet to figure out how to do in R is to create buffers around polygons
> (or just expand polygons). I searched the R-sig-geo archives (using
> Google) for "polygon buffer" and "transform polygon" but haven't found
> anything to get me started. Thanks in advance for your ideas,

Vector export and import in the spgrass6 package and v.buffer in GRASS 
works too. Using QGIS under Windows, it is pretty painless, starting Rgui 
in the GRASS shell; if the geometries are very complex, it takes some 
time. readVECT6() on the output geometries does need a fix (in the next 
release 0.4-2), because the imported data frame only has a single column 
and the data frame dimension gets dropped. The attached image is from a 
detailed bit of the North Carolina coast from the data sets supporting the 
forthcoming third edition of the GRASS book.

Roger

>
> Peter
>
>

-- 
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