On Tue, 29 Nov 2011, Sam Rabin wrote:
Hello all. I'm trying to write a new shapefile and am running into a weird
issue. After I import the new shapefile into QGIS, I can see all the polygons
in the attribute table, but none of them show up on the map no matter how I
play with the projections.
Here is some code that isolates the problem:
library("maptools")
spdf_1 <- readShapePoly("original.shp")
spdf_2 <- readShapePoly("original.shp", proj4string=CRS(as.character("+proj=utm
+zone=19 +south +datum=WGS84 +units=m +no_defs")))
writeSpatialShape(spdf_1, "output_1")
writeSpatialShape(spdf_2, "output_2")
As you can see, I tried readShapePoly with and without CRS information,
but both output files exhibit the same problem. I've used
writeSpatialShape successfully in the past, and I don't know what I'm
doing differently here.
The functions in maptools neither read nor write *.prj files, only *.shp,
*.shx, and *.dbf (they use shapelib, which doesn't know about
projections). Setting the CRS makes no difference. Did you use writeOGR()
in rgdal before - the rgdal functions both read and write projection
information?
Hope this helps,
Roger
Thanks in advance for your help.
Sam Rabin
Graduate student
Princeton University
Ecology & Evolutionary Biology
[[alternative HTML version deleted]]
_______________________________________________
R-sig-Geo mailing list
[email protected]
https://stat.ethz.ch/mailman/listinfo/r-sig-geo
--
Roger Bivand
Department of Economics, NHH Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: [email protected]
_______________________________________________
R-sig-Geo mailing list
[email protected]
https://stat.ethz.ch/mailman/listinfo/r-sig-geo
