search for: dissimilarities

...ing 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 similarity / / > matrix (triangular)? / / > In Kaufman and Rousseeuw's FORTRAN implementation (1990), they showed an / / > option like this one: / / > "Maybe...

Dear All , Since dissimilarity is one of quality measures in clustering , I'm trying to access to the sum of dissimilarity as a whole measure. But after running my data using CLARA I obtain : 1128 dissimilarities, summarized : Min. 1st Qu. Median Mean 3rd Qu. Max. 0.033155 0.934630 2.257000 2.941600 4.876600 8.943700 But I can not find the sum of dissimilarity.How can i access to it? Thanks a lot Safari __________________________________________________ [[alternative HTML version de...

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

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

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 similarity matrix (triangular)? In Kaufman and Rousseeuw's FORTRAN implementation (1990), they showed an option like this one: "Maybe you already have correlations coefficients between var...

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

...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 message: Dissimilarities : x y NA Metric : mixed ; Types = I, I, I, I, I Number of objects : 2 Warning messages: 1: In min(x) : no non-missing arguments to min; returning Inf 2: In max(x) : no non-missing arguments to max; returning -Inf I welcome other alternative than gower. I expect the dissimilarity output give...

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 ***

Hello! I am R beginner and I have a question obout a simple matching. I have to datasets that i read in with: MalVar29_37<-read.table("MalVar29_37.csv", sep = ";") FemVar29_37<-read.table("FemVar29_37.csv", sep = ";") They look like this and show binary variables: V1 V2 V3 V4 V5 V6 V7 V8 V9 1 0 0 0 0 0 1 0 0 0 2 0 0 0 0 0 1

...elated and cannot be trimmed to the same length, I am at a loss for what to do. For a set with so many unrelated sequences of different lengths, the only thing I have been able to is an all-against-all BLAST to create the matrix, but this gives high scores for similarities, not high scores for dissimilarities. The only thought I had was to use the reciprocal of the BLAST score as some perverse measure of distance. I am not subscribed to the list, so can I ask for responses directly to my email address? Thank-you, Tom Isenbarger -- isen at plantpath.wisc.edu thomas a isenbarger (608) 265-0850

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)

Hello. I know my dissimilarity matrix but not my original data. Is there any way i could use the clustering function Mclust or EMclust with this dissimilarity matrix? or at least some equivalent of these functions? As this is model based clustering i dont know if it is actually possible to do it without the original data thanks in advance for your help [[alternate HTML version deleted]]

...shown below: samptest4<- scan (file = "samp-test4.txt") samptest4<- matrix(data = samptest4,nrow=8, ncol=4, byrow=T) library(MASS) library(arules) library(ape) #CFI<- numeric (M) CFI <- function(ctree) { (ctree$Nnode -1)/(length(ctree$tip.label) - 2) } #calculation of dissimilarities & construction of trees# #Calc Jacc disimi# disjacc <- dissimilarity(samptest4, y=NULL,method="jaccard") #Calc Dice disimi# disdice <- dissimilarity(samptest4, y=NULL,method="dice") #Construct Jacc dendro# tjacc<- hclust(disjacc, method = "average")...

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

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 background. I am working on a technique where individuals organize items based on how similar they perceive the items to be. For example, assume there are 10 items. Person 1 might group items 1,2,3,4,5 in group 1 and the...

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

Dear All, I?ve got a statistical question on calculating dissimilarities in R. I want to calculate the different types of dissimilarities on the ?flower? dataset found in the package ?cluster?. Flower is a data frame with 18 observations on 8 variables. Variable 1 and 2 are binary, variable 3 is asymmetric binary, variable 4 is nominal, variable 5 and 6 are ordered and...

I have 4 very large species lists and I would like to compare them. I have the following results from running Sorenson’s dissimilarity tests: Norfolk Fens compared to Suffolk Coastal Fens: QS=0.583961142689298 Norfolk Fens compared to Breckland Edge Fens: QS=0.714896020281379 Norfolk Fens compared to Other Fens:

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:

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") :