overlap between shapefiles

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
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" <karlashikev at gmail.com> wrote:

>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
>
>	[[alternative HTML version deleted]]
>
>_______________________________________________
>R-sig-Geo mailing list
>R-sig-Geo at r-project.org
>https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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 location of your rangemaps: there is no single best answer.

Tom 2

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" <karlashikev at gmail.com> wrote:

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

      [[alternative HTML version deleted]]

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