Displaying 20 results from an estimated 100 matches similar to: "precision warning in delaunayn function"
2008 Jan 26
1
How to apply the wilcox_test function to subsets ?
Dear R-forumites,
I want to apply a Wilcoxon test on subsets of the data frame mydata,
splitted using the myindice variable. When I send :
wilcoxtest <- by(mydata, mydata$myindice, function(x)
{wilcox_test(x$value~x$fact)})
I get :
Error in eval(expr, envir, enclos) : object "x" not found
whereas
wilcoxtest <- by(mydata, mydata$myindice, function(x)
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 03
1
distances between points in R^3
Dear R helpers,
I'm trying to write a numerical scheme for a boundary integral method
to solve an electromagnetic problem. This requires the computation of
the distance between points at the surface of an object (a sphere, in
my example). Here is my code,
> require(rgl)
> r<-1
> size<-10
> theta<-seq(0,2*pi,length=size*2)
> phi<-seq(0,pi,length=size)
> pc
2004 Aug 02
1
Very strange ACL issue
Hello,
I upgraded from Samba 3.0.2 to 3.0.4 on my Redhat Enterprise system and am
now seeing something very strange with POSIX ACL?s. We have several shared
directories setup with per-directory group permissions (In other words each
directory has its own group in active directory). This way if we want to
give a user access to a directory we just add them to the group. After
upgrading too 3.0.4
2004 Apr 05
1
Two major issues with Mac OS X clients
Hello,
I am having to major issues with Mac clients on our samba server. One
has to do with how the Mac vs. the PC locks files and the other has to do
with a very slow connection to one of our larger shares.
1.) File locking issue:
I am having a strange problem occur with shared excel and word files being
opened by multiple users. The problem appears to be a result of a Mac
opening the file
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
2012 May 11
1
Replacements for stdout and stderr guaranteed to be open in all versions of R
I maintain the geometry package, which integrates the Qhull C library
(http://qhull.org) into R. The Qhull function I hook into requires an
open FILE handle as one of its arguments. I had set this file handle to
stdout, but now R check NOTEs the presence of stdout, and the CRAN
maintainers asked me to get rid of these NOTEs.
Including the following defines means the checks are passed on CRAN:
2001 Dec 10
1
high dimensional convex hull
Does anyone know of a R package that will determine the convex hull of a
high-dimensional dataset (say 4-10 dimensions). I know chull works for
2D data.
I'm neophyte to R and convex hulls so please keep it simple.
Many thanks
Ben
--
Ben Stapley.
Biomolecular Sciences, UMIST, PO Box 88, Manchester M60 1QD.
Tel 0161 200 5818
Fax 0161 236 0409
2001 Sep 22
2
Finding a 3D convex hull in R
Dear List Members,
I'm presently carrying out morphological analysis of a data set of neuronal
structures. These are essentially 3D binary trees. In due course I will be
trying to use discriminant analysis or other methods to classify these
neurons based on morphological variables such as total tree length, segment
number etc.
I would like to calculate a 3D convex hull for a set of X,Y,Z
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,
2008 Oct 29
1
How to set read.table variables to vectors?
The summary stats for the xin and yin variables below are correct. However,
if I use plot(xin,yin), an exception is thrown saying that "object xin is
not found."
Also, it is apparent that I can't successfully replace the x and y vectors
with values from xin and yin.
The four plots on one panel are showing but the range of x and y is only
[0,1], and therefore, it seems like an
2011 Oct 12
1
reasonable theory?
Before coding this in C, I wanted to test the idea out in R.
But I'm unsure if the theory is well-founded.
I have a (user-supplied) black-box function which takes R^n -> R^3
and a defined domain for each of the input reals.
I want to send some samples through the box to determine an
approximation of the convex hull of the function's range.
(I'll use the library from
2005 Apr 14
0
[Bug 2607] New: Rsync logging time incorrectly
https://bugzilla.samba.org/show_bug.cgi?id=2607
Summary: Rsync logging time incorrectly
Product: rsync
Version: 2.6.4
Platform: x86
OS/Version: Linux
Status: NEW
Severity: normal
Priority: P3
Component: core
AssignedTo: wayned@samba.org
ReportedBy: kilburna@iservnetworks.com
2009 Nov 25
3
Concave hull
Dear friends,
Do you know how to calculate the CONCAVE hull of a set of points (2-
dimensional or n-dimensional)? is that possible in R? (With a "smoothing"
parameter of course).
Best,
--
Corrado Topi
Global Climate Change & Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529 at york.ac.uk
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
2004 Aug 04
1
What's ``impres''?
Dear all,
In one S+ program, I found the following code.
if (impres) cat("blah blah blah \n")
Would someone here like to tell me what's the counterpart in R to
impres in S+?
Thanks in advance!
Best wishes,
Jinsong
=====
(Mr.) Jinsong Zhao
Ph.D. Candidate
School of the Environment
Nanjing University
22 Hankou Road, Nanjing 210093
P.R. China
E-mail: jinsong_zh at yahoo.com
2007 Jul 13
0
convhulln {geometry} output from .call
Hi All,
convhulln {geometry} computes the convex hull of a set of points in n-
dimensions via .call, returning the hull itself, and also
"unavoidably generates a diagnostic report on an Rterm console." See
the example below.
I need to access the results of the diagnostic report (specifically
the computed hull volume) from within R, but I cannot see how.
I've looked at
2018 Jan 10
0
Problem with dbFD function in FD library
Dear all,
I have a question about FD package. I?m trying to calculate functional
diversity indices using insect data. My trait data includes dispersal
ability (0, 0.5, 1), body size (continuous) and five feeding guilds coded
as in percentages (for example; 0,0,0.5,0.5,0) since some of the species
can have two different feeding guilds. However, the package only calculates
when I run ?calc.Frich=
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