Message-ID: <5ED3CACC-F99E-4F6B-BDCA-BCEC0BBE71BB@csiro.au>
Date: 2009-05-25T08:24:16Z
From: Viscarra Rossel, Raphael (CLW, Black Mountain)
Subject: deleting grid points outside boundary
Hello,
I have been using gstat to krige maps over my study area.
The area is irregularly shaped and has quite a complex boundary.
I have made a regular (square) grid that covers my study area and made
my estimates on this grid.
Now that I have my maps, I would like to 'mask out' or delete the
areas in my map that are outside my study area - i.e. where I don't
have any data, where the interpolations don't make sense. Essentially,
I want to end up only with the estimates over my study area.
As I said, the boundary of the study area is quite complex so the
chull method will not work well. I have seen a few posts where this
was suggested.
I have the xy coordinates for the boundary (and a shape file) for the
study area. I am wondering whether I could overlay it over the grid
with my estimates and then use it to remove the bits on the grid that
I don't want and so end up with a map of only the estimates over my
study area.
Could someone help with this please?
Cheers
R.