Specifically,
http://sedac.ciesin.columbia.edu/data/set/gpw-v3-population-density/metadata#Spatial_Reference_Information
The answer is EPSG:4326
http://epsg.io/4326 (compare this to the info above)
CRS("+init=epsg:4326")
will do, no need for the whole proj string.
This is often the case with wo
To add to Don's recommendation, after you have the 3rd SpatialPolygons
object of the overlap or intersection, you may need to spTransform() them
to a projection where area makes sense, then use rgeos::gArea to compute
the areas. Which projections to use depends on the spatial scale and
general loc
In the rgeos package there are gIntersects() and gIntersection(), that
might be enough to get you started.
-Don
--
Don MacQueen
Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062
On 5/8/15, 10:46 AM, "Karla Shikev" wrote:
>Dear all,
>
>I'd like
As you've sent the same question to both lists, please report your results to
both lists.
-Original Message-
From: R-sig-ecology [mailto:r-sig-ecology-boun...@r-project.org] On Behalf Of
Karla Shikev
Sent: Friday, May 08, 2015 10:38 AM
To: r-sig-ecol...@r-project.org
Subject: [R-sig-eco
Dear all,
I'd like to take two shapefiles and to calculate the area of overlap based
on some world projection. Any suggestions about possible functions?
Thanks!
Karla
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They also have this page:
http://sedac.ciesin.columbia.edu/data/set/gpw-v3-population-density/metadata
On Thu, May 7, 2015 at 11:11 AM, Shaun Walbridge
wrote:
> The specific projection information is contained within the raster
> datasets you download, in the related ASCII, Bil or GRID file. The
