[R] Voronoi-Diagrams in R

[Boris Steipe]

deldir() uses Lee and Schacter's algorithm, while the geometry package is a (partial) implementation of Barber et. al's Quickhull. Since both algorithms are correct, they should give the same results for the same data.

How about you post a small input dataset and list the output that you need...


B.




On 2014-05-20, at 2:04 PM, Raphael Päbst wrote:

> Thank you very much, this looks promising.
> 
> I have a follow-up question however, probably due to my thickness when
> it comes to the underlying math.
> 
> I am translating (as closely as possible) some code that has
> originally been written for Mathlab and uses the delaunay() function
> there. Now, if I understand it correctly, Mathlab uses the same
> Qhull-Library as a basis, as does the Geometry-Package. So in theory
> delaunay(x) in Mathlab and delaunay(x) in R should give me the same
> results for the same x, where x is a matrix of coordinates.
> 
> If I use deldir(x1, x2) where x1 and x2 are the first and second
> column of that same matrix above, is there any chance to get the same
> result as with delaunayn() or at least something similar in format to
> the result of delaunayn()?
> 
> Many thanks again and please excuse my crude english.
> 
> Raphael
> On 5/14/14, Boris Steipe <boris.steipe at utoronto.ca> wrote:
>> Try:
>> 
>> install.packages("deldir")
>> library(deldir)
>> ?deldir
>> set.seed(16180)
>> x <- runif(20); y <- runif(20); window <- c(0,1,0,1)
>> tess <- deldir(x, y, rw = window)
>> plot.deldir(tess, wpoints="real", wlines="tess")
>> 
>> Cheers,
>> Boris
>> 
>> 
>> On 2014-05-14, at 8:18 AM, Raphael Päbst wrote:
>> 
>>> Hello everyone!
>>> I have returned to R after a longish break and am currently working on
>>> a project where I need Delaunay-Triangulations and Voronoi-Diagrams.
>>> If I understood it correctly, the Geometry-Package only offers
>>> functions for the Delaunay-Triangulation at the moment. Is this
>>> correct and if so, what would be the best way to get Voronoi-Diagrams
>>> as well?
>>> 
>>> Many Thanks in advance!
>>> 
>>> Raphael
>>> 
>>> ______________________________________________
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>> 
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>> 
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.