[R] Area of overlap between polygon and circle

[Eric Archer]

R-listers,

Given a polygon and a circle defined by its center coordinates and a 
radius, I would like to calculate the area of overlap.  I know that I 
can create a polygon from the circle and then use available packages to 
get the area of the intersection.  However, because the polygon is of a 
fixed size and I will be doing this for circles of varying sizes, I'm 
concerned about maintaining the appropriate amount of resolution with 
larger circles.   If there was already a package that did the above 
calculation without the creation of a circle polygon and would thus give 
an exact area, that would be preferred.  I have searched the archives 
and have not found a solution to this particular problem.  Thanks!

Cheers,
eric

-- 

Eric Archer, Ph.D.
NOAA-SWFSC
8604 La Jolla Shores Dr.
La Jolla, CA 92037
858-546-7121,7003(FAX)
eric.archer at noaa.gov
http://swfsc.noaa.gov/prd-etp.aspx

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