It sounds to me as though you are simply getting yourself flummoxed by
the fact that the different packages produce their output in different
formats. The information in the output will be the same (as Boris has
indicated) --- it will just be arranged differently. Learn to interpret
the output of each function (RTFM!) and you will find that there is no
problem.
cheers,
Rolf Turner
(author of "deldir")
On 21/05/14 09:33, Raphael Päbst wrote:
Thanks for the answer!
I'll post a sample tomorrow, I have however found the following:
triang.list() gives me the coordinates of the triangle's vertices,
while delaunayn() gives me the indices of those coordinates. Thus it
should be more or less simple to convert the output of deldir() into
that of delaunayn()
Once again, thanks!
Raphael
On 5/20/14, Boris Steipe <boris.ste...@utoronto.ca> wrote:
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.ste...@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?
______________________________________________
R-help@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.
