A quick solution could be to convert it into a SpatialPointsDataFrame
object (gridded(x) = FALSE), before doing the selection that broke your
script. If it still breaks, you might check whether the selection is empty.
--
Edzer
Roger Bivand schrieb:
On Wed, 18 Mar 2009, David Wahlund wrote:
On Wed, 18 Mar 2009, David Wahlund wrote:
Hi
I got the same error trying to do something similar. For me the
problem was with the polygon data. One of the shapes was corrupted. My
tip is to try and identify what polygon renders the error and confirm
that it is OK.
Yes, the underlying problem i
Hi
I got the same error trying to do something similar. For me the
problem was with the polygon data. One of the shapes was corrupted. My
tip is to try and identify what polygon renders the error and confirm
that it is OK.
-David Wahlund
On Wed, Mar 18, 2009 at 16:01, Wesley Roberts wrote:
> Dea
Dear R-sig-Geo'ers
I am currently trying to extract some NDVI values from a group of NDVI images
for specific shapefile polygons. I have 17 individual polygons and 23 NDVI
images. I have written the script below to select individual polygons and to
then extract the average NDVI within each poly