similar to: MDS with missing data?

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

Hi all, I'm trying to perform an MDS of some data that I have. When I use cmdscale everything is fine and I get some interesting results however, the tends to be low. What I wnat to do is compare this with the Non-Metric MDS using isoMDS or sammon. However, when I try using these I get the following message. Error in isoMDS(x.dist) : zero or negative distance between objects 2 and 4

Dear all, I'm trying to get a two dimensional embedding of some data using different meythods, among which princomp(), cmds(), sammon() and isoMDS(). I have a problem with sammon() because the coordinates I get are all equal to NA. What does it mean? Why the method fails in finding the coordinates? Can I do anything to get some meaningful results? Thank you very much Domenico

I've been unable to find a R package that provides the means of performing Clarke & Ainsworth's BIO-ENV procedure or something comparable. Briefly, they describe a method for comparing two separate sample ordinations, one from species data and the second from environmental data. The analysis includes selection of the 'best' subset of environmental variables for explaining

Dear all, I didn't find any graphical solution in the package "mva" to plot the canonical scores from a CCA (canonical correlation analysis). Does anybody knows how to plot or has anybody already programmed : - the map of the canonical scores, - the graph of the canonical weights, - the correlation circle i.e. the canonical loadings ? Thank you for help ...

Hi, I'm trying to do a non-metric multidimensional scaling using isoMDS. However, I have some '0' distances in my data, and I'm not sure how to deal with them. I'd rather not drop rows from the original data, as I am comparing several datasets (morphology and molecular data) for the same individuals, and it's interesting to see how much morphological variation can be

I'm looking to switch to Mac platform. Anyone had any experience with that? I'm expecting on a power G4 laptop later this week.... hope R behaves... -- dok

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,

Canberra distance is defined in function `dist' (standard library `mva') as sum(|x_i - y_i| / |x_i + y_i|) Obviously this is undefined for cases where both x_i and y_i are zeros. Since double zeros are common in many data sets, this is a nuisance. In our field (from which the distance is coming), it is customary to remove double zeros: contribution to distance is zero when both x_i

Canberra distance is defined in function `dist' (standard library `mva') as sum(|x_i - y_i| / |x_i + y_i|) Obviously this is undefined for cases where both x_i and y_i are zeros. Since double zeros are common in many data sets, this is a nuisance. In our field (from which the distance is coming), it is customary to remove double zeros: contribution to distance is zero when both x_i

Hi; I am working with the similarity matrix below and I would like to plot a two-dimensional MDS solution such as each point in the plot has a label. This is what I did: data <- read.table('c:/multivariate/mds/colour.txt',header=FALSE) similarity <- as.dist(data) distance <- 1-similarity result.nmds <- nmds(distance) plot(result.nmds) (nmds and plot.nmds as defined at

Hi, I'd like to perform Dufrene-Legendre Indicator Species Analysis for a multivariate regression tree. However I have problems with arguments of duleg(veg,class,numitr=1000)function. How to obtain a vector of numeric class memberships for samples, or a classification object returned from mvpart? thanks in advance -- Best regards, Agnieszka Strzelczak

hi, my attempt to install the package Hmisc v3.0-1 fails with the message: /usr/bin/ld: cannot find -lfrtbegin collect2: ld returned 1 exit status make: *** [Hmisc.so] Error 1 ERROR: compilation failed for package 'Hmisc' i'm at a loss here. any hints will be very much appreciated. i'm running: debian stable R version 2.0.1 gcc 2.95.4-14 g77 2.95.4-14 binutils 2.12.90.0.1-4

i know cmdscale and isoMDS inR can do classical and non-metric MDS.but i want to konw if there is packages can carry on "individual differences scaling" and "multidimensional analysis og preference"?both method are important one,but i can not find any clue on how to do it using R. anyone can help? thank you!

Hi, It seems like a number of people on this list can install rgl but have problem loading it. I found myself in the same situation too. I have tried the workaround of removing /usr/X11R6/lib from DYLD_LIBRARY_PATH, but it doesn't seem to work for me, I am still getting the same error (that everyone else seems to get). Can anyone give me some ideas on what else to try? I have Mac OS 10.3.5,

Dear R-help, I'm trying to create a simple R package that contains 3 string functions, but I have run into some problems: what are the correct permission for the files in the package directory? Yours faitfully, Rasmus * checking for file `stringfun/DESCRIPTION' ... OK * checking package directory ... OK * checking for sufficient/correct file permissions ... WARNING * Found the

Hi After trying a simple decorana analysis (from the vegan package) on a simple data frame which contains no NA's the following error was returned: > tt_decorana(covN) Error in decorana(covN) : NA/NaN/Inf in foreign function call (arg 1) Have any vegan users come across this error and know what can be done about it? Cheers, J

Dear Colleagues, As a novice I was trying to calculate Shannon diversity index using diversity function in vegan package and kept having same error message. Error in sum(..., na.rm = na.rm) : invalid 'mode' of argument My dataset is from microarray and have abundant missing values, so I tried labeling them as NA and 0, but still same error message. Shannon index is negative

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

Hi, I've been using R for a while now but I've got a problem with metaMDS (in the vegan package) that I can't quite figure out. I have a set of proportion data (from 0-1, rows sum to 1) that I apply metaMDS to using the command: nMDS.set=metaMDS(sqrt(test.set),distance="euclidean",k=3,zerodist="add",autotransform=FALSE) I am using a squared-chord distance