similar to: bootstrapping for clustering

Displaying 20 results from an estimated 4000 matches similar to: "bootstrapping for clustering"

2005 Sep 21
3
Clustering and bootstrap
Dear Listers, I emailed the list a few days ago about how to bootstrap a community matrix (species by sites) and get a consensus tree with node support. A friend pointed out that a similar question remained unanswered in 2004. I wish to re-word my question: is anyone aware of a package / method to obtain a majority-rule consensus tree from x distance matrices ? Is anyone using R to generate
2011 Apr 28
1
visualizing bootstrapped dendrogram
I want to classify bipolar neurons in human cochleas and have data of the following structure: Vol_Nuc Vol_Soma 1 186.23 731.96 2 204.58 4370.96 3 539.98 7344.86 4 477.71 6939.28 5 421.22 5588.53 6 276.61 1017.05 7 392.28 6392.32 8 424.43 6190.13 9 256.41 3850.51 10 249.17 3118.14 11 276.97 3037.29 12 295.30 3703.76 13 314.43 5265.97 14 301.15 5781.73 I
2014 Jul 28
1
Split PVClust plot
Dear All I'm using PVClust to perform hierarchical clustering, for the output plot I can control most of the graphical I need, however the plot is large and I would like to split it vertically into two panels one above the other. Is there a way to plot only part of a PVClust plot, I tried to convert it to a dendrogram with result2 = as.dendrogram(result) however I get the error message
2012 Dec 06
1
clustering of binary data
Good morning, I am analyzing a dataset composed by 364 subjects and 13 binary variables (0,1 = absence,presence). I am testing possible association (co-presence) of my variables. To do this, I was trying with cluster analysis. My main interest is to check for the significance of the obtained clusters. First, I tried with the pvclust() function, by using method.hclust="ward" and
2013 Dec 17
1
What is the formula of Pseudo-F statistic in capscale in vegan?
Dear R-help, We are conducting a distance-based redundancy analysis using capscale and then testing for statistical significance for six terms in the model for the constrained ordination using anova.cca in the vegan package. The significance test is sequential, i.e., testing for significance of a term only after accounting for all preceding terms. Could someone please provide us with either the
2011 Feb 16
0
y-axis slightly cut-off after printing plots to tiff
Hi Folks, I'm hoping someone could help me a bit. I have plotted the following: ########################################### tiff("plot7.tiff",units="cm",width=15,height=36,res=700) layout(matrix(c(1,2,3,4,5,6),3,1),widths=lcm(c(15)),heights=lcm(c(12,12,12)),respect=TRUE) plot.t1<-plot(data.dist,flot1.bray.hell,xlab="",ylab="Bray-Curtis dissimilarity
2016 Apr 21
1
Vegemite Function is Cowardly refusing
R version 3.2.2. library(vegan) I was to look at community tables from my dendrograms and am trying out the vegemite command. This is the error I get: Error in vegemite(apst, apst.clusters) : Cowardly refusing to use longer than 1 char symbols: Use scale I thought the problem was that I was using the log transformed data, but I tried it on the raw (which is single digit numbers), and still
2010 Aug 09
0
Fwd: RE: pvclust function
You should reply to the list, not just me, and even more because I cannot really help you!! My guess (but I don't know this package, and even less this function) is that pvclust() is expecting a matrix as the first argument. However, "cluster" is no data, it is a function. Why, I don't know. Take a closer look at ?pvclust, especially the "usage",
2007 Aug 22
1
distance by vegan
How to calculate sorensen (bray-curtis) distance by dist function within the vegan package? Cheers Duccio
2008 May 12
1
inserting mathematical symbols in lattice strip
I have tried without success to find a way including the square root symbol in lattice strips as part of my conditioning labels. I have tried supplementing by creating a list of vectors using the var.name function coupled with the expression function used in xlab/ylab. xyplot(adjusted_Rand_index~cluster|distance_measure, main="Level of agreement between partitions: Wards Method",
2004 Dec 10
1
How to circumvent negative eigenvalues in the capscale function
Dear All I am trying to do a partial canonical analysis of principal coordinates using Bray-Curtis distances. The capscale addin to R appears to be the only way of doing it, however, when I try and calculate a Bray-Curtis distance matrix either using Capscale or Vegedist (capscale I understand uses Vegedist anyway to calculate its distance matrix), R uses up all available memory on the computer,
2007 Aug 14
0
Comparing long species lists via Sorenson’s dissimilarity
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:
2010 Aug 09
1
(no subject)
Hi there, I have been trying to use the "pvclust" package but have been having some difficulties. This is the first time I have used R so I am sure the mistake I am making is a basic one. The data I have is a distance matrix and I have been using the command; fit <- pvclust(cluster, nboot=1000, method.dist="euclidean") to try and perform hierarchical clustering with
2008 Jun 16
0
pvclust distance matrix
Hello, I am attempting to assign significance levels to a UPGMA cluster analysis as part my doctoral research. The pvclust function works well but doesn't include the similarity index I need (morisita's) as an option for computing a distance matrix. Morisita's is available in vegdist in the VEGAN library but I am having a hard time getting the vegdist function to "direct
2010 Jun 09
1
ordisurf (pkg vegan) gives implausible result
I'm having trouble with the ordisurf function in the vegan package. I have created an ordination plot (cmdscale) of 60 samples based on Bray-Curtis dissimilarities, and would like to overlay various soil edaphic characteristics as possible clues to the clustering I observe in my plot. However, I find that ordisurf creates a surface on the plot that is a perfect, even gradient - and
2004 Apr 12
1
question on isoMDS
Hello everyone, I have a question on isoMDS. My data set (of vegetation) with 210 samples is in this way: Rotfoehrenau Lavendelweidenau Silberweidenau .... 067_Breg.7 0 2 0 .... 071_Dona.4 0 2 6 .... ... I want to do an isoMDS-analysis with the dissimilarity index
2006 Nov 10
2
Problems with metaMDS from vegan
Hello all, I recently used the Vegan library quite extensively (in the context of text similarity assessment) on an Ubuntu 6.06 LTS system with R version 2.2.1 (2005-12-20 r36812). The Vegan lib is version 1.6-10. I hit on a problem yesterday, though, when trying to install R and Vegan on two further computers - one Windows XP and one further Ubuntu 6.06 machine, taking either R version 2.4.0
2008 Aug 13
1
re placing default labels in lattice
Dear all, I am having a little trouble deciphering how to change the default x-axis labels in a lattice xyplot (or any type of lattice plot for that matter). I have tried using the "demo("labels") function but the code is truncated at precisely the wrong moment! All I am trying to do is to add superscript to two of the labels for which i tried using the expression function. It
2010 Jan 19
1
restricted permutations in permtest()?
Hallo List, I'm trying to implemement a restricted permutation scheme in permutest(). More precisely I have dependence in my data that should be allowed for in the permutation - I simulated the problem in the example of the vegan documentation p.24: library(vegan) data(varespec) ## Bray-Curtis distances between samples dis <- vegdist(varespec) ## First 16 sites grazed, remaining 8 sites
2011 Nov 15
0
Bootstrap values for hierarchical tree based on distaance matrix
I would like to get an hierarchical clustering tree with bootstrap values indicated on the nodes, as in pvclust. The problem is that I have only distance matrix instead of the raw data, required for pvclust. Is there a way to get it? fit1 <- hclust(dist) # an object of class '"dist" plot(fit1) # dendogram without p values library(pvclust) fit2 <- pvclust(raw.data,