Displaying 20 results from an estimated 2000 matches similar to: "k-means / role of 'nstart'"
2013 Jun 24
1
K-means results understanding!!!
Dear members.
I am having problems to understand the kmeans- results in R. I am applying
kmeans-algorithms to my big data file, and it is producing the results of
the clusters.
Q1) Does anybody knows how to find out in which cluster (I have fixed
numberofclusters = 5 ) which data have been used?
COMMAND
(kmeans.results <- kmeans(mydata,centers =5, iter.max= 1000, nstart =10000))
Q2) When I
2003 Feb 14
2
RODBC connection failed
I am trying to restart on R after 2 months stop. Start with previously
functioning procedure:
"ch<-odbcConnect("dBase Files")"
get
"Warning message:
ODBC connection failed in: odbcConnect("dBase Files") "
I have tried unsuccessfully different working directories.
The only change I see is that I am working with a new login account on
the same machine.
2009 Apr 26
2
eager to learn how to use "sapply", "lapply", ...
After a year my R programming style is still very "C like".
I am still writing a lot of "for loops" and finding it difficult to recognize where, in place of loops, I could just do the
same with one line of code, using "sapply", "lapply", or the like.
On-line examples for such high level function do not help me.
Even if, sooner or later, I am getting my R
2013 Jul 25
3
variación en los resultados de k medias
Buen día a todos.
mi pregunta es si alguien sabe si el algoritmo de k medias siempre da los
mismos resultados con los mismos datos de entrada. o si al correrlo dos
veces con los mismos datos de entrada se pueden obtener grupos distintos.
[[alternative HTML version deleted]]
2000 Aug 28
2
Windows / RODBC / Accented characters
A disturbing behaviour of R: an import of data using RODBC library
(Windows 98, R 1.1.1) recognizes accented characters in variables
names but these can't be manipulated further. See below:
> library(Rodbc)
> ch<-odbcConnect("Paradox Files")
> pollut<-sqlFetch(ch,Pollutio)
> pollut
Mortalit? Densit? Pollution
1 82 600 110
2 97 960
2013 Mar 13
1
Empty cluster / segfault using vanilla kmeans with version 2.15.2
Hello,
here is a working reproducible example which crashes R using kmeans or
gives empty clusters using the nstart option with R 15.2.
library(cluster)
kmeans(ruspini,4)
kmeans(ruspini,4,nstart=2)
kmeans(ruspini,4,nstart=4)
kmeans(ruspini,4,nstart=10)
?kmeans
either we got empty always clusters and or, after some further commands
an segfault.
regards,
Detlef Groth
------------
[R] Empty
2000 Aug 30
1
Memory management
Some naive questions:
1) How to remove a column in a data frame? I expected that rm would
work but this is not the case (e.g. rm(dat$yyy) gives Warning
message: remove: variable dat$yyy was not found). I only found to
assign NULL value (e.g.: dat$yyy<-NULL). Is it the right way?
2) Is the place formerly occupied by dat$yyy automatically gained by
R for other uses?
3) If t1 and t2 are 2 only
2000 Nov 24
1
groupe averages error
I want to get subsets averaged on numeric variables number 5:13 but I
get the error below that I cannot understand.
> is.factor(dat$Statut)
[1] TRUE
> s<-ave(dat[,5:13],dat$Statut)
Error in [<-.data.frame(*tmp*, , value = if (n) { :
Argument "i" is missing, with no default
Thanks in advance
---------------
Charles RAUX,
Laboratoire d'Economie des Transports
2000 Aug 31
2
Multiv / hierclust / plclust
I use hierclust (hierarchical clustering) in multiv package. In the
documentation it is said that plclust (plotting a dendrogram) is
available in S-plus. Can I find it anywhere (I have searched through
http://lib.stat.cmu.edu/S and found only quotations of plclust in
multiv) or is it only part of the S package (which I don't have)?
Thanks
---------------
Charles RAUX,
Laboratoire
2000 Sep 04
2
plot history, libraries, weights
3 general questions:
1) How can I have the plot History Recording automatically turned on
each time I start R (Windows)?
2) How can I have some libraries automatically loaded at R start?
3) As far as I know weights can be specified only for lm. How can I
take account of weights with a weighted sample in other models or
functions (table but also other multivariate and cluster techniques)?
Thanks
2005 Sep 20
2
script.aculo.us: pause before effect.appear
I''ve created a simple script (below) which calls the effect.appear script in
order to make a group of items appear at the page load. I would like to have
the images randomly appear at different times; e.g. the 3rd image might
start appearing 2 seconds after load, the 6th image immediately after load,
the first image 1 second after load, etc...
How can I achieve this affect?
---
2000 Aug 14
5
Writing a workable function
After searching in R- Introduction, FAQ, help... I don't understand
this:
I write a function in a file (.R):
tt <- function(mc) { date()
mc<-read.csv2("machines.txt",na.strings="")
date()
}
I source it in R and I type tt(). The answer is
> tt()
[1] "Mon Aug 14 11:18:25 2000"
>
The instructions following the first "date()" are ignored. Why?
2005 Nov 17
1
transforming table into data frame
Hello,
I would like to transform a contingency table (A x B) into a data
frame while keeping the cross-tabulation structure (i.e. rows =
levels of A, columns = levels of B). I have tried as.data.frame,
xtabs, etc... and always got a "flattened" list of 3 variables (A, B,
Freq).
How to do that?
Thanks in advance
Charles Raux
2000 Aug 23
1
3D perspective of a contingency table
How can I draw a 3D perspective of a contingency table, that is
showing 3D bars whose height is in proportion of the table cells?
---------------
Charles RAUX,
Laboratoire d'Economie des Transports
CNRS-Universit? Lumi?re Lyon 2-ENTPE
email : charles.raux at let.ish-lyon.cnrs.fr
http://www.ish-lyon.cnrs.fr/let
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
2001 Nov 15
1
ploting axes plaxes ?
I used in previous versions of R (R 1.1) to plot axes on projections of
factorial coordinates using the function plaxes. This doesn't exist any
more. Why this change ? No alternative ?
---------------
Charles RAUX,
Laboratoire d'Economie des Transports
CNRS-Universit? Lumi?re Lyon 2-ENTPE
email : charles.raux at let.ish-lyon.cnrs.fr
http://www.ish-lyon.cnrs.fr/let
2004 Sep 06
1
A naive lsoda question....
Hello,
I am an R newbie, trying to use lsoda to solve standard
Lotka-Volterra competition equations. My question is: how do I
pass a parameter that varies with time, like say, phix <- 0.7 +
runif(tmax) in the example below.
# defining function
lotvol <- function(t,n,p){
x <- n[1]; y <- n[2]
rx <- p["rx"]; ry <- p["ry"]
Kx <-
2007 Jul 09
1
factanal frustration!
Hi.
It seems that nearly every time I try to use factanal I get the following
response:
>faa2db1<-factanal(mretdb1,factors=2,method="mle",control=list(nstart=25))
Error in factanal(mretdb1, factors = 2, method = "mle", control =
list(nstart = 25)) :
unable to optimize from these starting value(s)
>
In the case cited above, mretdb1 is synthetic data created
2009 Jun 10
1
Weird behavior in receive_data function
Dear List,
I'm trying to get diff/removed data and it's offset out. So I write a
functions in receive_data. When I run backup, I found there is a weird
behavior which I don't understand.
i = recv_token(f_in, &data) will receive (i = -1, offset2 = 0) some
where in the middle of the transfer procedure. That's to say, it's going
to transfer the first data block from sender,
2012 Aug 28
1
K-Means clustering Algorithm
I was wondering if there was an R equivalent to the two phased approach that
MATLAB uses in performing the Kmeans algorithm. If not is there away that I
can determine if the kmeans in R and the kmeans in MATLAB are essentially
giving me the same clustering information within a small amount of error?
--
View this message in context:
2013 Feb 03
1
Empty cluster / segfault using vanilla kmeans with version 2.15.2
Dear experts,
I am encountering a version-dependent issue.
My laptop runs Ubuntu 12.04 LTS 64-bit, R 2.14.1; the issue explained below
never occurred with this version of R
My desktop runs Ubuntu 11.10 64-bit, R 2.13.2; what follows applies to this
setup.
The data I'm clustering is constituted by the rows of a 320 x 6 matrix
containing integers ranging from 1 to 7, no missing data.
I applied