Displaying 20 results from an estimated 61 matches for "triangulate".
2008 May 29
1
akima interpolation and triangulation question
Dear all;
First of all, this is probably a more conceptual question than a
R-related one, but still want to give it a try. When working with the
interpolation function "interp" from the package akima and the
triangulation function "tri.mesh" from package tripack I've got NA's
for the interpolation and "error" for the triangulation. The data is
arranged in a
2008 Jan 11
9
Varying test data
This isn''t specific to RSpec, but is hopefully on-topic for this list.
I like (especially when "ping pong pairing") to write a spec, then
write the smallest amount of code I can to pass it (especially when
"ping pong pairing"). Sometimes this means hard-coding a return value,
which means another spec is needed to prove that the code is really
behaving as it
2010 May 09
1
Plot polygon in 3D with rgl
Dear R-helpers, an rgl-ers in particular,
what is the easiest way to plot a section of a plane in 3D, that is
given by the xyz coordinates of the outline?
Suppose I have a polygon - which I know for sure is a set of
coordinates on the same plane. One method I found is to use surf.tri
from the geometry package, and then plot the triangles with
rgl.triangles. This method is not perfect though,
2018 Mar 02
4
RADIUS
...tool. Worrying about it before those
> are researched, etc is to use an English idiom: putting the cart
> before the horse.
I?m surprised that wireless access point controllers, by default, do not
use the strength of the signal received from a device by three or more access
points to simply triangulate the position of the device. Of course, you
only get the positions of devices relative to access points, but once you
have that, you only need to use a map of the place that shows all the access
points and the positions of devices relative to them to figure out where
everyone is.
That?s a rather s...
2004 May 11
2
How to draw holes generated by gpclib using plot function
Hi.
I've tried to create a polygon with one hole by gpclib using following
example script.
holepoly <- read.polyfile(system.file("poly-ex/hole-poly.txt", package
="gpclib"), nohole = FALSE)
area.poly(holepoly)
plot(holepoly,poly.args=list(col="red",border="blue"))
And I noticed plot function couldn't draw polygons with holes correctly.
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,
+
2012 Jul 10
1
RGL 3D curvilinear shapes
Dear useRs,
I'm trying to simply fill in the area under a curve using RGL. Here' the set
up:
x <- c(0.75,75.75,150.75,225.75,300.75,375.75,450.75,525.75,600.75,675.75,
0.5,50.5,100.5,150.5,200.5,250.5,300.5,350.5,400.5,450.5,
0.25,25.25,50.25,75.25,100.25,125.25,150.25,175.25,200.25,225.25)
y <- c(0.05,4.91,9.78,14.64,19.51,24.38,29.24,34.11,38.97,43.84,
2018 Mar 07
2
RADIUS
...of getting that
Apparently Cisco can do it:
https://www.cisco.com/c/en/us/products/collateral/wireless/wireless-location-appliance/product_data_sheet0900aecd80293728.html
> sort of accuracy is to either have lots of pico cells so you know which
> AP a device is connected to, or be able to triangulate. WiFi has a
> reasonable range and devices like to hang on to an AP for as long as
> possible, even if they can pass off on to a closer more powerful one.
>
> I know retailers are looking at targeting customers via their location,
> but I think that currently needs the co-operation...
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
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
2011 Jul 13
2
3D density plot of point set
...hat would show a surface of constant
density which includes e.g. 50% of the points. Ideally, the surface
would be semitransparent, such that I can show two or three at the
same time.
Alternatively, if I would calculate the contour surfaces myself,
could I use R to semitransparently visualize a triangulated surface?
Thank you very much for your help
Lutz
2012 Jul 19
1
[tripack] error in trmesh
I am trying to triangulate a point set as follows:
> head(cbind(x,y))
x y
[1,] -78.1444 -60.4424
[2,] -78.1444 -58.4424
[3,] -78.1444 -56.4424
[4,] -78.1444 -54.4424
[5,] -76.1444 -60.4424
[6,] -76.1444 -58.4424
> length(x)
[1] 5000
> tri <- tri.mesh(x, y)
Fehler in tri.mesh(x, y) : error in trmesh
> tri &...
1998 Dec 04
1
contour labelling [was "Re: image ()"]
> From: Bill Simpson <wsimpson at uwinnipeg.ca>
> Subject: Re: contour labelling [was "Re: [R] image ()"]
> MIME-Version: 1.0
>
> > We may be missing the crux here: was it to have a means of
> > displaying such surfaces?
>
> Yes, bang on. I knew of the
> existence of the Delaunay code in the R libraries. Yes I want
> to make a picture that
2002 Nov 18
1
i386 floating point tweaking
Just been trying to get the polygon triangulation code from this
package: http://www-2.cs.cmu.edu/~quake/triangle.html to dyn.load into
R. Uh oh. Floating point exceptions.
Track it down to some FPU diddling that the author deems is necessary.
Here's my minimal code that breaks:
flipme.c:
#include <fpu_control.h>
void flipme(){
int cword;
cword=4210;
_FPU_SETCW(cword);
2004 Apr 26
2
Spatial Autocorrelation for point data
Hi R helpers,
Is there a function (package?) in R available which tests "spatial
autocorrelation" between points (e.g. vector layer of weather stations)?
(e.g. Moran's I...)
Via the archives we found out that there is a package 'spdep' which uses
grid data for testing spatial autocorrelation.
Thanks a lot,
Jan
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 Jan 30
1
New user...tips for spdep?
Hello List,
I'm a very new user to the R system. I'm only beginning to learn the
basics, but so far I've been able to do little more than try a few examples,
and of course begin reading the documentation.
My primary motivation for exploring R is the availability of tools like the
'spdep' package for calculating spatial statistics such as Geary's C and
Moran's
2017 Sep 25
0
Assertion in 'DwarfDebug.cpp'
Here are a couple things I would try to help triangulate on the problem.
Try a vanilla upstream compiler for an in-tree target. (IIRC you have your own target.) If that fails, it's pretty optimal for you because you should be able to reduce a test case and file a PR. If it doesn't fail, that suggests it's either something your target does...
2018 Mar 02
0
RADIUS
...>> are researched, etc is to use an English idiom: putting the cart
>> before the horse.
>
>
> I?m surprised that wireless access point controllers, by default, do not
> use the strength of the signal received from a device by three or more
> access
> points to simply triangulate the position of the device. Of course, you
> only get the positions of devices relative to access points, but once you
> have that, you only need to use a map of the place that shows all the access
> points and the positions of devices relative to them to figure out where
> everyone is...
2017 Sep 25
2
Assertion in 'DwarfDebug.cpp'
Since updating to the LLVM v5.0 Final tag, I am seeing a crash when I enable
'-g'. With a Debug build this hits an assertion at line #923 in
'lib/CodeGen/AsmPrinter/DwarfDebug.cpp':
assert(EndLabel && "Forgot label after instruction ending a range!");
The values of related variables at this time are:
'Begin' is: DBG_VALUE %I23, %noreg,