Thanks for the helpful reply. Coincidentally I found the isConvex() function
in the PBSmapping package (which has come to my rescue many times!). It's
based on fast C code.
I am in the process of writing my own is.monotone function given an
arbitrary axis and will post it once I am happy with its performance.

Thanks!
Markus

On Fri, Jun 19, 2009 at 11:48 AM, Nicholas Lewin-Koh <nikko@hailmail.net>wrote:

> Hi Markus,
> I don't know of any packages that have an exported test for this,
> but it would not be hard to write. For monotone it would probably be
> better to write something a little more general that could test
> if a polygon is x-monotone, y-monotone or rotationally monotone.
> I would offer to write this, but I won't be able to get to it for a
> while
> since we are in the process of moving, and my computer will soon be
> dismantled.
>
> Nicholas
>
> > ----------------------------------------------------------------------
> >
> > Message: 1
> > Date: Thu, 18 Jun 2009 09:40:47 -0400
> > From: Markus Loecher <markus.loecher@gmail.com>
> > Subject: [R-sig-Geo] is.convex, is.monotone for polygons
> > To: r-sig-geo@stat.math.ethz.ch
> > Message-ID:
> >       <bf460e020906180640m66d4fff9o55177e1d525c4163@mail.gmail.com>
> > Content-Type: text/plain
> >
> > Dear Rgeo users,
> > I am looking for a package/function which computes whether a given
> > polygon
> > is monotone, does that exist ?
> > I'd also be interested in a function which returns TRUE if the polygon is
> > convex, though that is probably very simple to code up (check every angle
> > ?)
> >
> > Thanks,
> >
> > Markus
> >
> >       [[alternative HTML version deleted]]
> >
> >
> >
>

	[[alternative HTML version deleted]]

