[R] Generating a polygon around points
clint at ecy.wa.gov
Fri Aug 15 17:25:42 CEST 2014
Your question seems to need an answer to, "How do you find a convex hull
on a sphere?" Google has many references.
Clint Bowman INTERNET: clint at ecy.wa.gov
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On Fri, 15 Aug 2014, Bob O'Hara wrote:
> I've been struggling for half a day on what should be a simple problem...
> I have a data frame of lat/long coordinates that describe a region, and I
> want to draw a polygon around them so I can use that as a boundary (to be
> thrown at INLA, but those details aren't important). The coordinates are
> almost on a regular grid: there is some variation in latitude (because
> we're on a globe).
> If the coordinates were on a regular grid, I could use as.owin() to create
> a mask, and go on from there (I have code that will work). But as.owin()
> doesn't like unevenly spaced points.
> Can anyone suggest a way to sort this out? Preferable without having to
> mess around transforming the coordinates.
> Bob O'Hara
> Biodiversity and Climate Research Centre
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