similar to: convex hull for cluster analysis

Displaying 20 results from an estimated 800 matches similar to: "convex hull for cluster analysis"

2010 Jul 07
2
how to define method for "+" function in a new class
Dear R developers, I have a new class, which I called "Molecule", and have tried to define = a "+" operation for 2 objects of this class. This is what I have written so far, although the method is not complete = (I'm trying to look at it at intermediate stages): setMethod( f=3D"+", signature(x=3D"Molecule",y=3D"Molecule"),
2009 Dec 10
1
question about centroid-linkage (cluster analysis)
Dear R community, I would be greatful if somebody could shed light on the following. I have created a set of 6 points to check how centroid agglomeration works in cluster analysis: > Y <- data.frame(x=c(-1,1,1,-1,10,12),y=c(1,1,-1,-1,0,0)) It is quite intuitive to understand that the last clusters to be joined will be {1,2,3,4} with {5,6}. Now, the centroid for the first cluster has
2010 Jul 23
1
greek letters in rgl plot3d
Dear RGL experts, I haven't been able to add greek letters to my rgl plot3d. I have tried "expression" with no success. Here is the interested bit: > library(rgl) > cb <- cube3d() > plot3d(cb,xlab=expression(alpha),ylab="",zlab="",box=FALSE,alpha=0.5) The expression(alpha) appears as "alpha", rather than as a greek symbol. I suspect greek
2010 Sep 09
1
rgl and lighting
Dear R community (and Duncan more specifically), I can't work out how to make additional light sources work in rgl. Here is the example. First I create a cube and visualize it: > cubo <- cube3d(col="black") > shade3d(cubo) Next I position the viewpoint at theta=0 and phi=30: > view3d(theta=0,phi=30) Next, I want to create a 2nd light source which diffuses red light
2011 Feb 26
2
sourcing a linux file with "system"
Dear R community, I would like to source a file in my linux system to set a few environment variables. I have tried: > system("source /home/james/build//ccp4-6.1.13/include/ccp4.setup") and got: sh: source: not found In fact, using Sys.which("source") I get an empty string. How can I source that ccp4.setup file from within an R session? J Dr James Foadi PhD Membrane
2010 Jan 25
1
summing a large, partitioned data frame
Dear R community, I'm trying to develop a fast way of summing specific rows of a large data frame. Here is an example of the kind of data frames I'm dealing with: > refls H K L M/ISYM BATCH I SIGI 43247 1 0 5 21 79 61.44117 2.20553 1040 1 0 5 257 6 15.16316 0.54431 2324 1 0 5 257 5 46.76152 1.67858 31515 1 0 5 259 60 57.97305
2007 Jul 05
3
unexpected result in function valuation
Dear all, I have a very small script to plot a function. Here it is: ########################################## sinca <- function(N,th) { return(sin((N+0.5)*th)/sin(0.5*th)) } plot_sinca <- function(N) { x <- seq(-5*pi,5*pi,by=pi/100) y <- rep(0,length=length(x)) for (i in 1:length(x))y[i] <- sinca(N,x[i]) plot(x,y,type="l",ylim=c(0,2*N+4)) return(c(x,y)) }
2008 Jun 05
2
Fourier Transform
Hello All, I wanted to perform a fourier transform on high frequency financial data. I have searched and have not found much on this topic for R. I was wondering if anyone has used any libraries for it or have come across any papers I may read. Many Thanks, Neil Gupta [[alternative HTML version deleted]]
2008 Mar 17
1
problems with rgl in Ubuntu 'gutsy'
Dear R users/gurus, I have recently installed Ubuntu 7.10 (Gutsy) on my Dell Latitude D520. First time for me, as I have always used Fedora. R installation using "apt" has proceeded fine, both for r-base and r-base-dev. Next, I need to install various other packages, "rgl" being first in the line. I have sorted some preliminaries by installing headers for X11 and Mesa: sudo
2008 Oct 08
0
issues with "write.table"
Dear R gurus and users, I'm having problems with the use of write.table. I have a 28-variables data frame create at each cycle of a loop; it can contain between 2000 and 3000 rows for each cycle. After each cycle the data frame is written out to a file with the "append=TRUE" option and then removed from memory. These are the couple of lines involved: > data2 <-
2007 May 31
1
recompile R using ActiveTcl
Dear all, While running some code requiring the "tcltk" package I have realised that my version of R was compiled with the Tcl/Tk libraries included in Fedora 6. It would be for me better to use the ActiveTcl libraries (which I have under /usr/local), and I'm aware that this probably means to recompile R with the proper configuration variables. But...is it by any chance
2010 Jan 18
0
new R package. How to hide data file
Dear R community, I'm in the process of writing a package. One of the functions reads a whole ascii file, full of data: > SYMINFO <- scan("/file/full/of/data.txt",what="character",sep="\n",quiet=TRUE) SYMINFO is now an array character with roughly 14000 elements. I thought the best way to use this file in the package was to list it, together with the
2007 Sep 07
1
Finding convex hull?
Dear UseRs, I would like to know which function is the most efficient in finding convex hull of points in 3(or 2)-dimensional case? Functions for finding convex hull is the following: convex.hull (tripack), chull (grDevices), in.chull (sgeostat), convhulln (geometry), convexhull.xy (spatstat), calcConvexHull (PBSmapping). I also would like to know if there is a function that can be used
2008 Feb 06
3
counting row repetitions without loop
Hi, I have a data frame consisting of coordinates on a 10*10 grid, i.e. > example x y 1 4 5 2 6 7 3 6 6 4 7 5 5 5 7 6 6 7 7 4 5 8 6 7 9 7 6 10 5 6 What I would like to do is return an 10*10 matrix consisting of counts at each position, so in the above example I would have a matrix where, for example, cell [4,5] contains 2 and [6,7] contains 3. At the
2009 Dec 04
1
multidimensional point.in.polygon??
Hi, I seek to identify those points in/outside a multidimensional convex hull (geometry::convhulln). Any suggestions? Background just in case I'm going down a really wrong road: Given an observed data set with one dependent/observed variable (Y) and multiple (3 to 10) independent/design variables (X1, X2, ...) I want to increase the number of points by interpolating. I'm using
2014 Apr 14
2
PXE booting UEFI
Good Afternoon, As per the installation guide, section 30.2.2 I?ve created an efidefault file at /var/lib/tftpboot/pxelinux/pxelinux.cfg/efidefault However, this file is never requested by the 64 bit PXE loader (bootx64.efi), as shown by tcpdump: 75 RRQ "/pxelinux/42272635-0011-5053-ACF2-82A100E615F2" octet tsize 0 blksize 512 59 RRQ "/pxelinux/01-00-50-56-A7-BA-BF"
2006 May 03
6
Xen Installation
Hi, I am installing xen first time. Install in suse linex 9.3 & red hat se 4.3 but i could not start xen domain. I have installation guide tar files & rpms of xen 3.0. but still i am not able co to configure xen 3.0. can some body help me how to configure xen. Awaiting for reply. __________________________________________________________ Yahoo! India Answers: Share what you
2020 Feb 06
4
No announcement for kernel 3.10.0-1062.12.1.el7
On our CentOS 7 servers I see there is a new kernel available when doing yum update: kernel 3.10.0-1062.12.1.el7 kernel-devel 3.10.0-1062.12.1.el7 However I am not able to find any announcement at redhat.com for this kernel. The only announcement I find is this from CentOS: https://www.mail-archive.com/centos-announce at centos.org/msg11573.html However that CentOS announcement links to
2013 Oct 17
3
Speeding up configuration log regeneration?
Hi, We run four-node Lustre 2.3, and I needed to both change hardware under MGS/MDS and reassign an OSS ip. Just the same, I added a brand new 10GE network to the system, which was the reason for MDS hardware change. I ran tunefs.lustre --writeconf as per chapter 14.4 in Lustre Manual, and everything mounts fine. Log regeneration apparently works, since it seems to do something, but
2008 Jul 19
1
estimating volume from xyz points
Dear all, I have several sets of x-y-z points and I need to estimate the volume that encompass all my points. Recently I got some adivice to show the "convex hull" of my points using geometry package (see code below). But now I need to calculate the volume of my set of points. Any advice are wellcome. Thanks in advance Miltinho Astronauta Brazil ----- require(geometry) library(rgl)