map to shapefile with projection info
On Wed, 6 Dec 2006 20:28:42 +0100 (CET),
Roger Bivand <Roger.Bivand at nhh.no> wrote:
[...]
canada <- map("world2Hires", "Canada", fill=TRUE, plot=FALSE)
fill=TRUE retrives polygons, otherwise you get line segments. For this example it now works. You can also make several retrieved island belong to the same Polygons object by giving them the same ID. There is an example on the pal2SpatialPolygons help page.
Thanks Roger, I didn't pick up that effect of the 'fill' arg. I noticed
also that I needed c("Canada", "Newfoundland"), as the latter island was
not included! I'll report this.
[...]
In rgdal (the PROJ.4 library is needed):
names <- sapply(slot(canada_sp, "polygons"), function(i) slot(i, "ID")) canada_spdf <- SpatialPolygonsDataFrame(canada_sp, data=data.frame(names=names, row.names=names)) writeOGR(canada_spdf, dsn=".", layer="canada", driver="ESRI Shapefile") list.files(pattern="canada")
Exactly. Thanks a lot. Cheers,
Seb