Displaying 20 results from an estimated 1000 matches similar to: "N-dimensional delaunay tesselation & voronoi diagrams"
2007 Nov 27
1
voronoi/Delaunay/Dirichlet tessellation on sphere in R or S?
There's Renka's STRIPACK, and TRIPACK, respectively, ACM TOMS Algorithms
772 and 751, and there's the R package "deldir" which does the Delaunay
for a plane, but does anyone have or know of the tessellation in R for a
sphere?
Also, is there a standard indexing scheme for Delaunay facets, and
perhaps of edges in such facets? I'd expect that to be a publication
reference,
2011 Feb 24
1
weighted Voronoi diagrams
Dear R-users,
Does anyone know how to do weighted Voronoi diagrams (Dirichlet
tesselation) in R? To be more specific, I have a set of coordinates for
tree locations on a plot, and I'm looking for a way to do the
tesselation so that the polygon size for each tree depends on the size
of the subject tree, and the size of its neighbors. So, the location of
the bisection between two trees
2006 Jul 19
2
voronoi tessellations
Okay, been working with tripack, seems the most mature package for this. Got it to work well with their test data set - data(tritest). When i tried random numbers to explore further, i am getting some results that don't reconcile.
example run this:
library(tripack)
y <- runif(100)
x <- runif(100)
vm <- voronoi.mosaic(x,y)
plot(vm)
par(new=T)
plot(x,y,col='blue')
when
2002 Feb 26
0
Package ``deldir'' available from CRAN.
A package for calculating and plotting the Delaunay triangulation and
the Dirichlet/Voronoi tessellation, of a planar set of points, is now
available from CRAN. The package is called ``deldir''.
The package consists of a port from Splus to R of a library section
which has been available for some time from the Splus software
segment of statlib. (The Splus library section is called
2004 Jun 01
0
qhull in R?
Hi,
does anyone know if there is an implementation
of qhull (http://www.qhull.org/) in R? anyone is
planning on it?
"Qhull computes convex hulls, Delaunay triangulations, halfspace
intersections about a point, Voronoi diagrams, furthest-site Delaunay
triangulations, and furthest-site Voronoi diagrams. It runs in 2-d, 3-d,
4-d, and higher dimensions. It implements the Quickhull algorithm
2012 Jul 26
2
precision warning in delaunayn function
Dear R helpers,
I try to use the 'delaunayn' function in the 'geometry' package for
Delaunay triangulation in 2 dimensions.
For the four following points, I get a warning message :
> coord=matrix(ncol=2,byrow=TRUE,c(622633,7073452,
+ 621228,7073517,
+ 621879,7071762,
+
2001 Apr 14
0
How to create polygons from voronoi objects in tripack?
Hello.
I'd like to convert voronois object created by tripack to polygons to use
them in GIS(Geographic Information Systems) software. I tried to create
voronoi objects by using following code.
> library(tripack)
> x <- rnorm(10)
> y <- rnorm(10)
> plot(x,y)
> v<-voronoi.mosaic(x,y)
> plot(v)
But from here, I could not create polygons.
Of course, I know
2018 Jan 25
0
Geometry delaunayn and deldir results, differing results from Octave due to decimal precision?
I just looked at the data at the URL you posted and it looks like it
consists
of all the points in a rectangular grid. When you triangulate a rectangle
it is
arbitrary whether you use the SW-NE or the SE-NW diagonal and that looks
like the only difference between the various algorithms.
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Thu, Jan 25, 2018 at 5:14 AM, Yuen, Kam <k.yuen at
2018 Jan 24
0
Geometry delaunayn and deldir results, differing results from Octave due to decimal precision?
"The question is, what is making the results for the R packages different
from each other?"
There are literally thousands of R packages, contributed independently by
thousands of people. There should be no expectation of consistency or for
that matter, "correctness", among them. Caveat emptor.
Only within the base R distribution, maintained and mostly written by the R
Core
2006 Apr 06
1
rounding of voronoi vertices using deldir()
Hello list,
I'm just getting started with using R - I have been trying over the past
day or so to work out a method for generating voronoi polygons for
PostGIS using SQL. I was able to put together a procedure which works
relatively well, but is somewhat inefficient. Someone on the PostGIS
list pointed me to the deldir() function in R, for which I can export a
text file with x/y coordinates
2018 Jan 24
4
Geometry delaunayn and deldir results, differing results from Octave due to decimal precision?
The problem:
I would like to translate the Octave algorithm in griddata.m to R.
Within the griddata algorithm calls are made to the Delaunay function. For the R translation I have found delaunayn within the "geometry" package and also the deldir package.
Both do similar things but give slightly different results depending on the input.
The question is, what is making the results for the
2005 Nov 13
4
voronoi
Is there any pure r code to do delaunay or voronoi diagrams?
Thanks!
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[[alternative HTML version deleted]]
2008 Feb 07
1
Voronoi
Hello everyone
I have a problem with tripack package, I want to perform a Voronoi
tessellation on a specific domain (I have the shape file), in order to
weight my climatic data with the area ... How Can I do it?
Thank you very much
Andrea
2007 Aug 27
0
Monmonier algorithm
Hello,
Here is a late answer, but an answer nonetheless to the question I asked
almost one year ago on this list:
> On Wed, 29 Mar 2006, Thibaut Jombart wrote:
>> Hello list,
<http://tolstoy.newcastle.edu.au/R/help/06/03/24318.html#24322qlink1>
/>> /
/>> does anyone know if Monmonier algorithm is available in R? I've
checked /
/>> several spatial
2010 Dec 16
0
Convert tileplot's trellis to shapefile/ Add values to voronoi polygon
I would like to create a voronoi map that can show me point values like the
ones in colum street_cle. I was able to do it in tileplot(latticeExtra) like the
ones attached, and with the following commands:
xy=list(x=x2$X, y=x2$Y)
xy$street_cle <- x2$street_cle
tileplot(street_cle~ x*y, xy)
But this is a trellis. Is it possible to be converted to a shapefile or image so
I can plot it using
2007 May 09
1
voronoi.mosaic chokes?
Hi all,
I am running R 2.5.0 under Windows XP Media Center Edition. Here's a
problem that's been stumping me for a few days now, and I can't find
anything useful in the archives. I am using voronoi.mosaic (tripack
package) to create proximity polygons for a study of vegetation
competition and dynamics. The points lists are read in from a file for
each plot, then 8 duplicates
2006 Apr 26
1
accessing a SOAP based web service from R
Hi,
I have a number of web services that run on a server and can be
accessed via SOAP as well as by creating a specific URL.
Now, for certain services, the argument that I need to send is about 10
to 20 characters and the URL approach works fine. However if the
argument is a few kilobytes I would rather create a SOAP packet and send
that off.
So my first question is: is there a package that
2012 Sep 24
0
Deldir() Thiessen Polygons Problem
Good evening to all.
I find myself trying to create some Thiessen Polygons, in order to finish a
meteorology research.
This is the script I found to create the Polygons:
*
*
*voronoipolygons <- function(x) {*
* require(deldir)*
* if (.hasSlot(x, 'coords')) {*
* crds <- x@coords *
* } else crds <- x*
* z <- deldir(crds[,1], crds[,2])*
* w <- tile.list(z)*
* polys
2007 Jun 08
0
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2003 Nov 21
3
plot map of areas
Hi all,
Given a number of points (x,y) in a plane, I'd like to plot a map of
polygons, so that
1) each polygon contains exactly one point
2) the polygon defines the area for which this specific point is
closer than any other point.
It's a bit like a map of areas "influenced" by that point, and it's
obviously a matter of intersecting the perpendicular bisectors