Displaying 20 results from an estimated 3000 matches similar to: "Computing very large distance matrix"
2004 Feb 04
1
Clustering with 'agnes'
Hello,
I had a question regarding clustering using the agnes() function from the 'cluster' package.
I was wondering if anyone knew how I can identify cluster points after running the agnes function.
For example, I created a dataset with points randomly scattered around (0,0), (0,1) and (1,0). After clustering, the dendrogram shows all the clustered points and I get the ordering and
2011 Jun 27
3
New to R, trying to use agnes, but can't load my ditance matrix
Hi,
I'm mighty new to R. I'm using it on Windows. I'm trying to cluster using a
distance matrix I created from the data on my own and called it D10.dist. I
loaded the cluster package. Then tried the following command...
> agnes("E:D10.dist", diss = TRUE, metric = "euclidean", stand = FALSE,
> method = "average", par.method, keep.diss = n < 1000,
2007 Nov 28
2
Clustering
Hello all!
I am performingsome clustering analysis on microarray data using
agnes{cluster} and I have created my own dissimilarity matrix according to a
distance measure different from "euclidean" or "manhattan" etc. My question
is, if I choose for example method="complete", how are the distances
between the elements calculated? Are they taken form the dissimilarity
2006 Jan 05
1
Memory limitation in GeoR - Windows or R?
Dear Aaron,
I am really a tool user and not a tool maker (actually an ecologist
doing some biostatistics)... so, I take the liberty of sending a copy of
this e-mail to the r-help list where capable computer persons and true
statisticians may provide more relevant information and also to Paulo
Ribeiro and Peter Diggle, the authors of geoR..
I really feel that your huge matrix cannot be
2008 Sep 02
2
cluster a distance(analogue)-object using agnes(cluster)
I try to perform a clustering using an existing dissimilarity matrix that I
calculated using distance (analogue)
I tried two different things. One of them worked and one not and I don`t
understand why.
Here the code:
not working example
library(cluster)
library(analogue)
iris2<-as.data.frame(iris)
str(iris2)
'data.frame': 150 obs. of 5 variables:
$ Sepal.Length: num 5.1 4.9 4.7
2016 Mar 04
2
GSOC 2016 project on Ranking
Hello Sir,
I am a third-year student at the Department of mathematics at IIT
Kharagpur. I have good experience in Information Retrieval and Machine
Learning. I have read many chapters of the book Introduction to Information
Retrieval. Recently I am doing a project on tagging a question on a Q&A
Forum using ranking the tags and probabilistic inference. I also have
software development
2003 Jun 17
2
Clustering quality measure
Hi all,
I am running a series of experiments where after manipulating my data I
run several clustering algorithms (agnes, diana and a clustering method
of my own) on the data. I wanted to determine which clustering method
did the best job, so therefore I had defined my own quality measure
using two criteria: compactness of the data within the clusters
themselves and the amount of seperation
2006 May 10
1
help with writing output from two different arrays to two columns in an output file
Hi,
I am very new to R and I have written the following block of code to
generate a gamma distribution for variable x (which is an array) and a
function "y" whose array values depend on the individual array values of
"x".
The code is as follows:
n=1000
x=rgamma(n,1.5,2)
y=vector("numeric",n)
for (i in 1:n){
y[i]=(2937/50000*exp(-1/1000*x[i])/x[i])
}
now I want to
2013 May 02
2
Calculating distance matrix for large dataset
Dear R users
I wondered if any of you ever tried to calculate distance matrix with very
large data set, and if anyone out there can confirm this error message I
got actually mean that my data is too large for this task.
negative length vectors are not allowed
My data size and code used
dim(mydata_nor)[1] 365000 144> d <- dist(mydata_nor, method = "euclidean")
Here my
2009 Oct 21
2
squared euclidean distance
Dear R-Help-Team,
I would like to cluster my data using the ward-method. In several papers I
read (e.g. Bahrenberg) that it is neccesary to use the "squared euclidean
distance" with the ward-method. Unfortunatelly I cannot find this term in r
as a method for measuring the distance.
Does anybody have an idea?
Thanks in advance,
Carolin
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2003 May 07
1
-means, hybrid clustering or similar implementations on R
Hi,
I would like to know if someone knows an extended implementation of k-means in R to find appropriate number of clusters for a given k-dimensional data.
Also, I am working on clustering for forecasting, if someone is interested or has knowledge on implementational details please mail me, I would appreciate it.
Regards
Skanda Kallur
"Cogito, ergo sum" (I think, therefore I
2018 Mar 15
3
stats 'dist' euclidean distance calculation
Hello,
I am working with a matrix of multilocus genotypes for ~180 individual snail samples, with substantial missing data. I am trying to calculate the pairwise genetic distance between individuals using the stats package 'dist' function, using euclidean distance. I took a subset of this dataset (3 samples x 3 loci) to test how euclidean distance is calculated:
3x3 subset used
2011 Jul 06
1
relative euclidean distance
Hi,
I would like to calculate the RELATIVE euclidean distance. Is there a
function in R which does it ?
(I calculated the abundance of 94 chemical compounds in secretion of
several individuals, and I would like to have the chemical distance
between 2 individuals as expressed by the relative euclidean distance.
Some compounds are in very low abundance whereas others are in high
abundance,
2012 Aug 24
3
Euclidean distance function
Hi,
I should preface this problem with a statement that although I am sure this
is a really easy function to write, I have tried and failed to get my head
around writing functions in R. I can use R where functions exist to do what
I want done, but have found myself completely incapable of writing them
myself.
The problem is that I have a table with several rows of species and several
columns of
2006 Feb 05
3
Cluster Analysis - Number of Clusters
Hello,
I'm playing around with cluster analysis, and am looking for methods to
select the number of clusters. I am aware of methods based on a 'pseudo
F' or a 'pseudo T^2'. Are there packages in R that will generate these
statistics, and/or other statistics to aid in cluster number selection?
Thanks,
John.
--
2004 May 28
6
distance in the function kmeans
Hi,
I want to know which distance is using in the function kmeans
and if we can change this distance.
Indeed, in the function pam, we can put a distance matrix in
parameter (by the line "pam<-pam(dist(matrixdata),k=7)" ) but
we can't do it in the function kmeans, we have to put the
matrix of data directly ...
Thanks in advance,
Nicolas BOUGET
2008 Jan 31
3
fastest way to compute the squared Euclidean distance between two vectors in R
I have a program which needs to compute squared Euclidean distance
between two vectors million of times, which the Rprof shows is the
bottleneck. I wondered if there is any faster way than my own simple
function
distance2 = function(x1, x2)
{
temp = x1-x2
sum(temp*temp)
}
I have searched the R-help archives and can not find anything except
when the arguments are matrices. Thanks for any
2010 Sep 02
1
how to cluster vectors of factors
Hello all
I wonder what can i use to cluster vectors which composed of several
factors.
lets say around 30 different factors compose a vector, and if the factor is
present then it encoded as 1, if not presented then it will be encoded as 0.
I was thinking of using hierarchical clustering, as i know the distance
between two vector were calculated through euclidean distance function, but
i dont
2010 Jun 24
2
Euclidean Distance Matrix Analysis (EDMA) in R?
I am studying on statistical shape analysis, I wonder is there any way or
package available that I can perform Euclidean Distance Matrix Analysis
(EDMA I or EDMA II) in R...
thanks
Gokhan
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2011 Apr 05
2
Euclidean Distance in R
Hi
1. I have two raster files *.asc (identical size)
2. The data in each contain presence or absence data in each cell
represented by a 1 or 0 respectively
3. I would like to take the location of each 1 (presence cell) in
raster file 1 and measure the euclidean distance to the nearest 1
(presence cell) in raster file 2.
Obviously in some cases there will be overlap so the distance will be zero.