Message-ID: <CAN-Z0xV2RDKU8-rcP_Ko_=n6RjSq=sBf3TJT2mhn8sVEP_Xmkw@mail.gmail.com>
Date: 2014-08-15T15:22:55Z
From: Bob O'Hara
Subject: Generating a polygon around points
In-Reply-To: <7bfcd4af-f256-4caa-a287-5f87938e5db4@email.android.com>
Unfortunately my region isn't convex, and I don't want to end up predicting
the distribution of a forest-dwelling bird in the Atlantic ocean...
Bob
On 15 August 2014 17:15, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote:
> Not really sure I understand your constraints, but perhaps
>
> RSiteSearch("convex hull ")
>
> might help?
> ---------------------------------------------------------------------------
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> Sent from my phone. Please excuse my brevity.
>
> On August 15, 2014 7:51:37 AM PDT, Bob O'Hara <rni.boh at gmail.com> 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
>
>
--
Bob O'Hara
Biodiversity and Climate Research Centre
Senckenberganlage 25
D-60325 Frankfurt am Main,
Germany
Tel: +49 69 798 40226
Mobile: +49 1515 888 5440
WWW: http://www.bik-f.de/root/index.php?page_id=219
Blog: http://occamstypewriter.org/boboh/
Journal of Negative Results - EEB: www.jnr-eeb.org
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