Displaying 20 results from an estimated 600 matches similar to: "weighted Voronoi diagrams"
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
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,
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
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
2006 Mar 14
1
help on moran's I index of point pattern, not areal pattern
hi,friends,
we all know that moran's I index and Geary'C index can be used to test
spatial autocorrelation in both the area data and point data, but i only can
find something on how to calculate on the data of area, and can't find the
methods to perform it on the point data, could anybody give me some
information, thanks in advance!
--
Kind Regards,
Zhi Jie,Zhang ,PHD
Department of
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
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
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
2005 Nov 13
4
voronoi
Is there any pure r code to do delaunay or voronoi diagrams?
Thanks!
---------------------------------
[[alternative HTML version deleted]]
2003 Jan 30
2
nearest neighbour interpolation
Dear Help List,
My name is Matt Oliver. I have been using R for about a year and find it very
helpful. However, I have a need for a function that I cannot find. I am not very
good at programming so I thought I would ask the group.
I have an irregular grid of data (x = Longitude, y = Latitude). Each pair of my x,y
has a categorical value. Obviously linear or any other numerically based
2006 Oct 03
2
maybe use voronoi.findrejectsites?
hi all members,
please, i need you help... now a i´m working with veronoi polygons in a
area with projections, but i need cut the polygons left. On other words, i
need cut the polygons in the worked area.
R help say that use the command voronoi.findrejectsites, but in this
command i need put the numbers, any way...this command not cut!! do you
can help me?
Thank you for help me!
José Bustos
2006 Aug 14
1
lasso for variable selection
For "importance" it's probably best to stick with absolute values of
coefficients, instead of value of the penalty parameter for which the
coefficients changed to non-zero.
Friedman skipped a lot of details on his rule ensemble in that talk, due to
time constraint. In his implementation he was using his own algorithm,
PathSeeker, for which paper and software are available on his
2003 Jun 30
2
spatial correlation test
hello,
I want to do a test for spatial correlation.
I tried it with geary.test() but I don't understand the required input.
x= a numeric vector the same length as the neighbours list in listw (my
sampled data, I assume)
listw= a listw object created for example by nb2listw (well when I check
nb2listw() I get to "neighbours - an object of class nb" - but I couldn't
figure
2006 Oct 10
1
Surfaceplot3D with wireframe
Hi,
I want to make a surface3D plot of a landscape. I have cordinates (x, y, z)
recorded with a GPS. The datapoints are not evenly distributed within the
rectangular area.
To do a fast 3D plot I used following.
> library(grid)
> library(lattice)
> v <- read.table("clipboard")
> names(v) <- c("x", "y", "z")
> wireframe(z ~ x * y, data =
2004 Aug 24
8
[PATCH] Support for accounting based on uid/gid
Hi,
I noticed shorewall''s accounting feature didn''t support the owner
module of iptables. Well, I needed the feature so here''s a patch that
makes it possible. However, there''s one thing you might review
carefully as I wasn''t sure what''s the best way to work around it. You
must use chain OUTPUT in order to make -m owner work (iptables
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
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
2004 Nov 24
8
[PATCH] Configurable variable for iptables executable
Hello,
I want to test Shorewall''s IPsec feature. It requires patched netfilter
(and kernel but that''s another story). I didn''t want to replace my
distribution''s iptables package with my own compilation so I installed
it to another prefix. Now Shoreall uses the iptables command found
first in $PATH. I don''t think this is the most elegant way. I
2019 Mar 05
2
request to have edit access to wiki
Hi all,
I did try to do this myself as I thought Tuomas had introduced himself
and gotten wiki access for other pages ... but my skills with the #acl
markup have atrophied and I couldn't make it work. :)
I'd like Tuomas to have access so there is a clear commit record of him
having down the work, and in the future to collaborate on any
adjustments to that page.
best regards,
- Karsten
2003 Jan 13
1
Extensively slowing for(i in 1:400) statement
Hello!
Here is what I have tried to do:
1. I have 400 time series
2. pull one serie at a time from ODBC
3. calculate some descriptives and regressions (about 50 statistic per
serie)
4. store the results in the data frame
The problem:
The time consumed in each loop seems to grow linearly. I used the date()
function for timing each loop and time spent in loop seems to grow at the
speed of 0.6 *