I would like to create buffers in polygons, surrounding my original polygon. However, I want to keep only the "outside polygon", not include also original polygon. In Buffer in ArcGIS I can just set function OUTSIDE_ONLY and I have my buffer zone only (http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Buffer%20(Analysis)).
However I didn't find a way how to make it in R? I've tried both, {rgeos} and {raster}. I know I can delete my original polygon later ({rgeos}), but is there a way how make it happen while creating buffers?
# stack overflow
library(rgeos)
# create polygon
p1 = readWKT("POLYGON((2 2,-2 2,-2 -2,2 -2,2 2))")
# create two buffers - one wth {raster}, one with {rgeos},
# both covers also original polygon !
b.r<-buffer(p1, width = 1, dissolve = T)
gb.r<-gBuffer(p1, width = 0.3, byid = T)
# keep only buffer
buff<- gDifference(b.r, p1)
# how can I create OUTSIDE_ONLY polygon without gDifference inter-step???