Displaying 20 results from an estimated 4000 matches similar to: "similarity matrix conversion to dissimilarity"
2004 Dec 09
1
more clustering questions
Sorry to bother you kind folks again with my questions. I am trying to
learn as much as I can about all this, and I will admit that I don't
have the proper background, but I hope that someone can at least point
me in the correct direction.
I have created a test matrix for what I want to do:
s1 s2 s3 s4 s5
s1 10 5 0 8 7
s2 5 10 0 0 5
s3 0 0 10 0 0
s4 8 0 0 10 0
s5 7
2005 Jul 20
4
poisson fit for histogram
I haven't been an R lister for a bit, but I hope to enlist someone's
help here. I think this is a simple question, so I hope the answer
is not much trouble. Can you please respond directly to this email
address in addition to the list (if responding to the list is
warranted)?
I have a histogram and I want to see if the data fit a Poisson
distribution. How do I do this? It is
2004 Dec 13
1
UPGMA
R-help folks:
Thanks in the past for your help. I have another question that I hope
has a simple answer. I have searched the R home pages and the R-help
archives with no hits. How can I cluster data in R using UPGMA?
I am not subscribed to the list (can't keep up with all the traffic!),
so I would appreciate it if you could email directly to me (or to the
list and to me).
Thanks,
Tom
2004 Jun 29
1
PAM clustering: using my own dissimilarity matrix
Hello,
I would like to use my own dissimilarity matrix in a PAM clustering with
method "pam" (cluster package) instead of a dissimilarity matrix created
by daisy.
I read data from a file containing the dissimilarity values using
"read.csv". This creates a matrix (alternatively: an array or vector)
which is not accepted by "pam": A call
2004 Sep 08
8
isoMDS
Dear List:
I have a question regarding an MDS procedure that I am accustomed to
using. I have searched around the archives a bit and the help doc and
still need a little assistance. The package isoMDS is what I need to
perform the non-metric scaling, but I am working with similarity
matrices, not dissimilarities. The question may end up being resolved
simply.
Here is a bit of substantive
2001 May 30
3
Transformation of dissimilarity or distance matrix
Dear List,
is there an elegant (or even not elegant) way how to transform
dissimilarity or distance matrix A
(or, in general, arbitrary symmetrical matrix) by transposition of rows and
columns into a form
closest to "block diagonal" matrix B?
The matrix A is adjusted the following way
A[A<epsilon] <-0 #(epsilon is given "small" number)
B: (in its ideal form)
2007 Jun 20
1
Dissimilarity
Hello Stephen,
I am happy that you help me. Thanks a million.
It is a good feeling that you confirm my assumption that dsvdis is
not able to deal with missing data, because it says me that I am not
completely incapable.
Okay now I have the problem what to do.
I used this function ´cause there is an option to weight columns
differently what I haven´t found in other functions.
But now I
2004 Feb 06
2
Converting a Dissimilarity Matrix
Hi all,
I'm trying to perform a hierarchical clustering on some
dissimilarity data that I have but the data matrix I have already
contains the dissimilarity values. These values are calculated using
a separate program. The dissimilarity matrix in complete with no
missing values but the hclust, and agnes routines require it in the
form produced by daisy or dist. Is there any of converting
2013 Sep 06
1
Fwd: calculating dissimilarity index of islands (vegan and betapart)
Dear List,
This is Elaine, a postgraduate studying in bird distributions in East Asia.
I want to calculate Simpson dissimilarity index,
based on a presence/absence matrix of bird species in islands in East Asia.
(matrix row: 36 islands/matrix column: species ID)
(R package vegan to make NMDS and R package betapart)
In most papers using vegan for NMDS and betapart for dissimilarity
2010 Dec 28
3
Jaccard dissimilarity matrix for PCA
Hi
I have a large dataset, containing a wide range of binary variables.
I would like first of all to compute a jaccard matrix, then do a PCA on this
matrix, so that I finally can do a hierarchical clustering on the principal
components.
My problem is, that I don't know how to compute the jaccard dissimilarity
matrix in R? Which package to use, and so on...
Can anybody help me?
Alternatively
2001 Jan 09
2
PAM clustering (using triangular matrix)
Hi,
I'm trying to use a similarity matrix (triangular) as input for pam() or
fanny() clustering algorithms.
The problem is that this algorithms can only accept a dissimilarity
matrix, normally generated by daisy().
However, daisy only accept 'data matrix or dataframe. Dissimilarities
will be computed between the rows of x'.
Is there any way to say to that your data are already a
2003 Jan 07
2
Extracting means for given strata from dissimilarity object
Is there a way of extracting mean distance or dissimilarity for a given
strata from a 'dist' or 'dissimilarity' object, e.g. extract mean distances
for each species in Anderson's iris data?
data(iris)
iris.dist<-dist(iris[,1:4])
then what?
Mikkel Grum, PhD
Genetic Diversity Scientist
International Plant Genetic Resources Institute (IPGRI)
Sub-Saharan Africa Group
***
2013 Dec 08
3
Why daisy() in cluster library failed to exclude NA when computing dissimilarity
Hi,
According to daisy function from cluster documentation, it can compute
dissimilarity when NA (missing) value(s) is present.
http://stat.ethz.ch/R-manual/R-devel/library/cluster/html/daisy.html
But why when I tried this code
library(cluster)
x <- c(1.115,NA,NA,0.971,NA)
y <- c(NA,1.006,NA,NA,0.645)
df <- as.data.frame(rbind(x,y))
daisy(df,metric="gower")
It gave this
2008 Mar 19
1
one/multi-dimensional scaling with incomplete dissimilarity matrix
Dear David,
you asked this question a while ago on the R mailing list and got no
answer. I have the same problem and was wondering if you had found a solution
Cheers
Loic
Loic Thibaut, PhD candidate,
ARC Centre of Excellence for Coral Reef Studies,
School of Marine Biology, James Cook University,
Townsville,
Qld, 4811, Australia.
Tel + 61 747 815 735, Fax: + 61 747 251 570, email:
2011 Jul 08
1
Visualizing a dissimilarity matrix in Euclidean space
Hi,
I have a set of nodes and a dissimilarity matrix for them, as well as a csv
file in which the diss matrix has been converted to [node_1, node_2,
dissimilarity] format. I would like to visualize this as a graph in
Euclidean space (that is, similar nodes clumped together in clusters),
rather than the seriation visualization given by dissplot(). I am using
Network WorkBench for my
2008 May 15
1
metaMDS using Dissimilarity matrix
Hello R-user community!
I am running R 2.7.0 on a Power Book (Tiger). (I am still R and
statistics beginner)
Presently I try to run the function metaMDS (vegan) using an existing
dissimilarity-matrix.
As I would like to start with this matrix I thought I could just give
the matrix using the x= -argument
Test<-metaMDS(x=Dist.Gower)
Fehler in inherits(comm, "dist") :
2006 Apr 07
1
fuzzy classification and dissimilarity matrix
Hello,
I want to make a fuzzy classification from a dissimilarity matrix
(calculated with daisy from package 'cluster'). I have tried to use
fanny (package cluster) but I have the same problems than described in a
previous message
(http://tolstoy.newcastle.edu.au/R/help/05/05/4546.html) i.e. it always
gives me two clusters in the results (even if k is different from 2)
with the same
2016 Apr 12
1
Dissimilarity matrix and number clusters determination
Hi,
I already have a dissimilarity matrix and I am submitting the results to
the elbow.obj method to get an optimal number of clusters. Am I reading
the below output correctly that I should have 17 clusters?
code:
top150 <- sampleset[1:150,]
{cluster1 <- daisy(top150
, metric = c("gower")
, stand = TRUE
, type = list(symm
2001 Oct 18
1
object of class "dissimilarity"
R users,
Does anybody know how to convert a square matrix of distances (X^2
distances, actually) into an object of class "dissimilarity" so that the
cluster package can used it?
Thanks.
Jord? L?pez
Unv. Aut?noma de Barcelona
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2006 Nov 09
1
dissimilarity matrices
Dear All,
I have a dissimilarity matrix which I happily convert to a distance object
by running:
X <- as.dist(Y)
and I can happily now run either hclust(X) or agnes(X).
So that the various bits of output are labelled correctly I would dearly
like to be able to give names to the columns and rows of X, as would happen
if I ran:
mydata<-read.table("clipboard",header=T)