[R-sig-Geo] Intersect shapefiles

[Alex Mandel]

Union creates a merged shape including all parts of input objects.

Intersection creates a shape of the overlapping portions of input objects.

I'm not clear on the goal from the initial email so I don't know which
is better in this case.

Enjoy,
Alex

On 02/18/2016 07:55 AM, Worrall, James -FS wrote:
> 
> I would have thought gUnaryUnion, but then I can't understand from the documentation what the difference is between that and gIntersection.
> 
> -----Original Message-----
> From: R-sig-Geo [mailto:r-sig-geo-bounces at r-project.org] On Behalf Of chris english
> Sent: Thursday, February 18, 2016 7:24 AM
> 
> John,
> 
> As Loic suggests, rgeos::gIntersection will get you there. Look closely at his naming of objects and your example code using spTransform. With his approach, each object has its own name; whereas your approach overwrites Rain_poly_merge the second and third time and the final object (third) is the 2008 maize yield. So read your shapefiles into differently named objects and use Loic's approach.
> 
> Chris
> 
> 
> 
> 
> 
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