polygon buffers?
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