On 30/10/14 03:16, Michal Kvasnička wrote:
Hello.
I have a set of points in 2D. I can construct Voronoi polygons around them
with deldir package and function from this page:
http://stackoverflow.com/questions/9403660/how-to-create-thiessen-polygons-from-points-using-r-packages
What I need is to find the list of all polygon neighbors of each original
point. (Let us say that each original point is represented with its Voronoi
polygon. These polygons are numbered. I have to find a list of all indices
of the polygons that share a line segment with polygon 1, polygon 2, etc.)
I can go through all line segments of all polygons and search for the
polygon that shares the line segment but I guess there is a better way to
do it. Can you help me to find it please?
Look at the "dirsgs" component of the object returned by deldir(). It
has two columns named "ind1" and "ind2". These are the indices of pairs
of points which are Delaunay neighbours, i.e. points such that the line
joining them is intersected by an edge of a Dirichlet (Voronoi) tile.
This should provide you with the information you want.
cheers,
Rolf Turner (author of the "deldir" package)
--
Rolf Turner
Technical Editor ANZJS
______________________________________________
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.
