Displaying 20 results from an estimated 3000 matches similar to: "selecting optimal cluster validation score"
2008 Mar 02
0
Runtime error
Hi everybody!
I try to implements Self-Organizing Maps with R and the Kohonen package.
I have made an algorithm that try differents width and height. For each
step, Silhouette index, Davies-Bouldin index and Dunn index are computed.
However, there is always after severals minutes a *Runtime error* appears on
the window:
Microsoft visual c++ runtime library
"this application has requested
2011 Mar 02
2
clustering problem
Hi,
I have a gene expression experiment with 20 samples and 25000 genes each.
I'd like to perform clustering on these. It turned out to become much faster
when I transform the underlying matrix with t(matrix). Unfortunately then
I'm not anymore able to use cutree to access individual clusters. In general
I do something like this:
hc <- hclust(dist(USArrests), "ave")
2003 Jun 09
1
estimate the number of clusters
Dear All,
I am using Silhouette to estimate the number of clusters in a microarray
dataset.
Initially, I used the iris data to test my piece of code as follows:
library(cluster)
data(iris)
mydata<-iris[,1:4]
maxk<-15 # at most 15 clusters
myindex<-rep(0,maxk) # hold the si values for each k clusters
mdist<-1-cor(t(mydata)) #dissimlarity
2011 Dec 09
1
Help understanding cutree used for Dunn Index
Basic question:
Is it correct to assume that when using cutree to set the # clusters
(say k=4), cutree determines the clusters by the largest distances
among all potential clusters?
I've read the R help for cutree and am using it to define the number
of groups to obtain Dunn Index scores (using clValid library) for
cluster analysis (using Euclidean Distance and Ward's method)
More
2012 Aug 12
0
Different cluster orderings from cutree() and cut.dendrogram()
Hi!
I just discovered that cutree() and cut.dendrogram() do not assign the
same cluster numberings when called on the same tree. More specifically,
cutree() assigns cluster numbers by order of appearance in the data,
while cut.dendrogram() sorts clusters by height (see example below). I
guess this is for historical reasons?
I'm hit by this difference when I want to get a vector of cluster
2007 Oct 16
0
doubts about Silhouette
Sorry for the long message. I'm doing my best to try to explain myself.
I have fitted a spline to my data, I have fitted a spline, filled in
the missing data by replicating the spline coefficients associated to
the last node. I obtained a number of dendograms by different
combination of distance and link-method by calling DIST and AGNES.
The agglomerative coefficient is very high (~ 0.99) for
2010 Dec 31
1
Silhouette function problem
Hi,
I am using code below to get a plot that will show me on the X axis the
number of clusters and on the Y axis the cluster average widths. However I
am getting this error:
Error in summary(silhouette(cutree(d, x), dist(iris[, -5])))$si.summary :
$ operator is invalid for atomic vectors
the code I am using is:
avgs<-sapply(1:20,function(x)
summary(silhouette(cutree(d,x),
2008 Jun 13
1
Output of silhouette (cluster package)
Dear R users,
I am mailing you about the graphical output of silhouette (cluster
package)
From the example of silhouette in help(silhouette):
> ar <- agnes(ruspini)
> si3 <- silhouette(cutree(ar, k = 5), # k = 4 gave the same as pam()
above
+ daisy(ruspini))
> plot(si3, nmax = 80, cex.names = 0.5)
from which one may conclude that group 1 is composed by
2007 Oct 26
2
cut.dendrogram and cutree
Hi!
In the example:
hc <- hclust(dist(USArrests), "ave")
dend1 <- as.dendrogram(hc)
dend2 <- cut(dend1, h=70)
Do the branches "Branch 1", "Branch 2", "Branch 2"...in dend2$upper
str(dend2$upper)
--[dendrogram w/ 2 branches and 4 members at h = 152]
|--[dendrogram w/ 2 branches and 2 members at h = 77.6]
| |--leaf "Branch 1" (h=
2005 Jun 28
0
R-help Digest, Vol 28, Issue 28
On Tuesday 28 June 2005 15:30, r-help-request at stat.math.ethz.ch wrote:
Re : 37. Re: A. Mani : colours in Silhouette (Mulholland, Tom)
>
> Message: 37
> Date: Tue, 28 Jun 2005 09:08:24 +0800
> From: "Mulholland, Tom" <Tom.Mulholland at dpi.wa.gov.au>
> Subject: Re: [R] A. Mani : colours in Silhouette
> To: <a_mani_sc_gs at vsnl.net>, <r-help at
2002 Feb 08
0
packages for extracting subtrees
Hi. I did write those functions, and sent them (I thought) to one of the R
maintainers to see whether they would be appropriate for inclusion (because
I'd seen some requests on the mailing lists).
However, I'm happy to post them -- I should have thought of it before.
WARNING: I've tested these functions on some data arising in my work and
also on the USArrests data that comes with
2011 Aug 25
1
question on silhouette colours
I'm fairly new to the silhouette functionality in the cluster package, so apologize if I'm asking something naive.
If I run the 'agnes(ruspini)' example from the silhouette section of the cluster package vignette, and assign colours to clusters, two clusters have what appear to be incorrect colours in the silhouette plot.
library(cluster)
data(ruspini)
ar<- agnes(ruspini)
2012 Aug 12
0
Index Values in NbClust
Dear All,i applied "NbClust", to my data to find optimum number of clusters, and got following resultsNow, i don't know how to read these results. more precisely, i would like to know, how to see which method is more precise for my data considering these index values.your help is needed...thanks in advance
Eliza Botto
> dput(Eliza)structure(list(All.index = structure(c(2, 3, 4, 5,
2002 Mar 05
1
no labels when plotting dendrograms
I'd like to be able to cut dendrograms at a height I specify
and then plot the resulting subtrees. I wanted to use the
dendrogram object for this purpose because there doesn't seem
to be a canned way to cut a hclust object and get a list of
hclust objects, but there is a function (cut) that does that
for dendrograms. The problem I'm having is that when I plot
a dendrogram, I
2011 Jan 05
1
List to a summary table
Hi
Suppose you have the code below. The result I get from the cat function is
from the avgs object. Now, I have 30 diferent objects like this and I wish
to make a summary table, something like:
Avgs1 Avgs2
Avgs3
i= 2 average= 0.515983i i= 2 average= 0.746983 i= 2
average= 0.2665983
i= 3 average=
2009 Jun 20
1
png() resolution problem {was "Silhouette ..."}
Hallo Sebastian,
>>>>> "SP" == Sebastian P?lsterl <sebp at k-d-w.org>
>>>>> on Sun, 14 Jun 2009 14:04:52 +0200 writes:
SP> Hello Martin,
SP> I plotting the silhouette of a clustering and storing it as png. When I
SP> try to store the image as png the bars are missing. The bars are plotted
SP> when I use x11 or
2006 May 02
1
Cluster validation methods
Hi All,
Except the "Rand Index", "Dunn Index" and "Silhouette width", are there
other cluster validation methods in R? Could you please also specify the
function?
Thanks!
[[alternative HTML version deleted]]
2009 Sep 21
0
Help needed to clarify hclust and cutree algorithms
Dear R Helpers,
I read carefully the documentation and all postings on the hclust and cutree functions, however some aspects of the tree ordering and cluster assignment performed by these functions remain unclear to me, so I would very much appreciate your help in making sure I get them right.
Here is an example, with values chosen to illustrate the problems.
I have a set of five profiles
2011 Dec 12
1
how to colour labels (each label with a colour) in a dendrogram?
Hello to all,
I still have this doubt.
I'd like to colour the different labels of my dendrogram each one with a
different colour. How can I do? I guess I could do using *edgetext* and
then *t.col* or* lab.col* but I don't know how to add edgetext to my
dendrogram. Can you help me please?
Example:
require(graphics); require(utils)
hc <- hclust(dist(USArrests), "ave")
(dend1
2001 Aug 22
1
cutree (PR#1067)
Full_Name: Anja von Heydebreck
Version: 1.3.0
OS: Alpha Unix
Submission from: (NULL) (141.14.19.61)
Hi,
I repeatedly obtained meaningless results from the function 'cutree'
in the 'mva' package, when the argument 'h' was greater or equal to
the maximum height occuring:
> library('mva')
> y
[,1] [,2] [,3] [,4]
[1,] 0 1 -1 1
[2,] 0 -1