There is a triangulation example in the geosphere vignette: http://cran.r-project.org/web/packages/geosphere/vignettes/geosphere.pdf This is for spherical (longitude/latitude) coordinates, but perhaps it is useful to look at when developing something similar for xy coordinates.
Robert On Wed, Jul 18, 2012 at 2:09 PM, Barry Rowlingson < [email protected]> wrote: > On Wed, Jul 18, 2012 at 7:24 PM, Robby Marrotte <[email protected]> > wrote: > > Hello everyone, > > > > I have data where for every tracked individual we have 3 radio-telemetry > xy > > locations with an orientation (0-360 deg). What I want to do is create > > triangles which represent the possible locations of each individual. It > > seems quite simple, but I haven`t found a script which does this yet. I > > tried Hawth`s tools but it doesn't have anything like this. > > Hawth? Who that? > > I'm no expert in this, but I've had a good search for anything that > might do this in R, but can't find anything either. Found some > literature (Russell V. Lenth appears to be quite the man for this) and > some of the techniques in "On Finding The Source Of A Signal" in > Technometrics 1981 by him should be easy to implement in R if anyone > has a spare day... > > The naive method of intersecting the lines should be doable with > high-school geometry, but Lenth warns: > > """ > A simple method for estimating (x, y) would be to use the > componentwise average of the n(n - 1)/2 bearing intersections > (assuming the observation points are distinct and that each bearing > intersects all other bearings). However, these points of intersection > are not stochastically independent. Moreover, their error structures > depend on the distances from the corresponding observation points as > well as the angle of intersection. Thus it would be difficult to > determine the statistical properties of such an estimator.""" > > Barry > > _______________________________________________ > R-sig-Geo mailing list > [email protected] > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
