# Location polygon from triangulation data

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## Location polygon from triangulation data

 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. Thanks         [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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## Re: Location polygon from triangulation data

 On Wed, Jul 18, 2012 at 7:24 PM, Robby Marrotte <[hidden email]> 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 [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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## Re: Location polygon from triangulation data

 There is a triangulation example in the geosphere vignette: http://cran.r-project.org/web/packages/geosphere/vignettes/geosphere.pdfThis 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 < [hidden email]> wrote: > On Wed, Jul 18, 2012 at 7:24 PM, Robby Marrotte <[hidden email]> > 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 > [hidden email] > https://stat.ethz.ch/mailman/listinfo/r-sig-geo>         [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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## Re: Location polygon from triangulation data

 Thanks, i might try looking at the R packages and if I get frustrated I'll check out the book. 2012/7/18 Robert J. Hijmans <[hidden email]> > > 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 < > [hidden email]> wrote: > >> On Wed, Jul 18, 2012 at 7:24 PM, Robby Marrotte <[hidden email]> >> 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 >> [hidden email] >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo>> > >         [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo