similar to: voronoi/Delaunay/Dirichlet tessellation on sphere in R or S?

Displaying 20 results from an estimated 200 matches similar to: "voronoi/Delaunay/Dirichlet tessellation on sphere in R or S?"

2004 Aug 31
0
N-dimensional delaunay tesselation & voronoi diagrams
Hi, I've been looking for functions that can do delaunay tesselation and generate voronoi cells. I came across deldir and tripack but both seem to be restricted to 2D points. Are there any packages that can do a tesselation in N dimensions? I know that Matlab and Mathematica use the qhull package to provide functions for this. Does anybody know of any R packages that do this (maybe by calling
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
2005 Nov 13
4
voronoi
Is there any pure r code to do delaunay or voronoi diagrams? Thanks! --------------------------------- [[alternative HTML version deleted]]
2015 May 18
2
Tessellation shaders get MEM_OUT_OF_BOUNDS errors / missing triangles
Hello, I've been debugging a few different tessellation shader issues with nouveau, but let's start small. I see this issue on my GK208 with high frequency, and I *think* I've seen it once or twice on my GF108, but it's exceedingly rare, if it does happen. I don't have a GK10x to test on, unfortunately, but I assume it'll have the same issue as the GK208. The issue is
2015 May 26
2
Tessellation shaders get MEM_OUT_OF_BOUNDS errors / missing triangles
One additional observation that I just made is that on GK208, the blob apparently doesn't use the result of S2R Rx, SR_INVOCATION_ID wholesale in TCS. It either passes it through a I2I.S32.S32 Rx, |Rx| (i.e. absolute value), or even more paradoxically, shl 2; shr 2; which removes the top *2* bits, rather than just the top 1. However I see no such behaviour on GF108. I'm going to test out
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
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
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
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
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
2003 Aug 14
1
Contouring irregular xyz data via TIN
Dear, I have XYZ data available in a MySQL database. I get it out, can plot the data with the plot() function, load it into a geoR datastructure. But what I actually would like to do is a simple contouring of the data based on a no Kriging interpolation such as TIN based. I know the first thing I shold do is interpolate a full matrix for the region I have my points for, then contour should
2010 Oct 15
0
tessellation from biological data in spatstat
Hi, I'm new to this mailing list so apologies if this is too basic. I have confocal images 512x512 from which I have extracted x,y positions of the coordiates of labelled cells exported from ImageJ as a.csv file. I also have images that define an underlying pattern in the tissue defined as areas of different pixel values 0 or 255 (also 512x512) I've exported these images as .txt
2010 Oct 16
0
Spatstat Tessellation error
Hello R Users, I am trying to do a quadrat count defined by covariate properties in spatstat. I have read my elevation raster into R (from ascii) and converted to class "im" for use in spatstat. Now I have point data of class "ppp" which window is the same extent as the elevation image. I can conveniently plot the image and the points on the image as follows:
2010 Oct 20
0
Spatstat: tessellation problems.
Hello R Users, I am trying to do a quadrat count defined by covariate properties in spatstat. I have read my elevation raster into R (from ascii) and converted to class "im" for use in spatstat. Now I have point data of class "ppp" which window is the same extent as the elevation image. I can conveniently plot the image and the points on the image as follows:
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
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
2015 May 17
14
[PATCH 00/12] Tessellation support for nvc0
This is enough to enable tessellation support on nvc0. It seems to work a lot better on my GF108 than GK208. I suspect that there's some sort of scheduling shenanigans that need to be adjusted for kepler+. Or perhaps some shader header things. Even with the GF108, I still get occasional blue triangles in Heaven, but I get a *ton* of them on the GK208 -- seemingly the same issue, but it's
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
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