In the past I have encountered numerical shapefile attributes stored as
factors, not numbers. So you would have to make the following change to
Friderike's code to select by area:
require(rgdal)
Ctries=readOGR(dsn='C:/data/datasets/HornOfAfrica', layer='HornOfAfrica',
p4s=NULL)
str([EMAIL PROTECT
,
Friderike
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Xin LIN
Sent: 05 September 2008 10:07
To: r-sig-geo@stat.math.ethz.ch
Subject: [R-sig-Geo] How to remove polygons according to their attributes?
Hi, everyone
I have a shapefile with many adjace
Hi, everyone
I have a shapefile with many adjacent polygons in. Each has a series of
attributes such as ID and area. Now I want to remove some of them based on
attributes, e.g. to remove polygons with areas less than a given value. How
can I proceed?
Thanks a lot.=)
Lin Xin
--
Lin Xin
Departme