similar to: vegan metaMDS

Displaying 20 results from an estimated 200 matches similar to: "vegan metaMDS"

2009 Oct 06
1
previous.best in metaMDS
Dear R-community, dear Jari Oksanen! I use metaMDS (package vegan) to calculate NMDS. In a lot of papers I read that it is recommended to use previous best solutions as a new starting configuration to get better results and to avoid local minima. On the help page I found that a previous.best-command is already implemented in metaMDS: metaMDS(comm, distance = "bray", ...,plot = FALSE,
2009 Oct 14
2
metaMDS NMDS: use of alternative distances?
Dear r-helpers! How can I integrate other distances (in the form of a dist object) into function metaMDS? The problem: metaMDS needs the original data.frame for the calculation and only the default distances of function vegdist are allowed. Any suggestions are greatly appreciated! Thank you, Kim -- Jetzt kostenlos herunterladen: Internet Explorer 8 und Mozilla Firefox 3.5 - sicherer, schneller
2011 Sep 23
2
metaMDS
Hello R-user community, I am applying the function metaMDS. However, I would like to know if there is any option to export the data I got from the axis as a data frame. I have tried as.data.frame.list but is not working. Any suggestion? Thank you in advance for your help, Lineth [[alternative HTML version deleted]]
2007 Aug 24
1
Adding new points to a metaMDS ordination ("vegan" pkg)
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
2009 May 27
1
vegan metaMDS question
The design decision in metaMDS says that it uses: Minchin, P.R. (1987) An evaluation of relative robustness of techniques for ecological ordinations. Vegetatio 71, 145-156. This is the paper that I found by the same name. Is this the correct reference? Minchin, Peter R.1987. An Evaluation of the Relative Robustness of Techniques for Ecological Ordination. Vegetatio. Vol. 69, No. 1/3: 89-107.
2009 Sep 03
1
Confusion metaMDS and CA
Hello, I read a lot about ordination, but I am still confused... I have data on species presence/absence for 8 different sites and I would like to represent my species and the sites on an ordination plot to see if some species are associated with specific sites. I used metaMDS function, which displays both sites and species and it seems to work well. However why are most people using CA instead of
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") :
2008 Apr 14
1
Vegan R^2 and tau values for metaMDS
I am using the function metaMDS with jaccard distances to ordinate a set of constituent by site matrix. I can post this data if it would be helpful, but it is large to include in an email. I can also provide reproducable code if necessary. I would like to get an R^2 value for the axes of the ordination configuration that I get with metaMDS in the vegan package is there a way to do this- is it
2008 Dec 30
1
why stress value remains so high after invoking of metaMDS
Hello everyone! metaMDS(cm, distance = "euclidean", k = 2, trymax = 50, autotransform =TRUE, trace = 1, plot = T) (cm is a similarity matrix, in which values are positive integers or 0) I use this command to run NMDS on my matrix "cm". But the stress is very high after analysis. About 14. Actually, there is no improvment comparing with using isoMDS.
2013 May 27
1
metaMDS with large dataset produces 'insufficient data' warning
Greetings everyone, I am running MDS on a very large dataset (12 x 25071 - 12 model runs with 25071 output values each), and also on a very much reduced version of the dataset (randomly select 1000 of the 25071 output values). I would like to look at similarities/dissimilarities between the 12 model runs. When I use metaMDS on the full dataset, I get a warning message: Warning message: In
2008 May 23
0
how to compute "explained variance" in metaMDS(vegan)?
Dear all, I used metaMDS (vegan) to generate two NMDS axis and now I would like to know the amount of variance explained for each axis. Is there a way to do that? kind regards, miltinho [[alternative HTML version deleted]]
2008 Dec 29
0
stress value remains so high(metaMDS)
metaMDS(cm, distance = "euclidean", k = 2, trymax = 50, autotransform =TRUE, trace = 1, plot = T) (cm is a similarity matrix, in which values are positive integers or 0) I use this command to run NMDS on my matrix "cm". But the stress is very high after analysis. About 14. Actually, there is no improvment comparing with using isoMDS.
2011 Mar 10
0
Stress in metaMDS from vegam package
Hi, I have a newbie doubt. I try to use metaMDS in R, it is OK, but the stress that I get is 16.32, in other programs stress is showed like 0.173. I don't find a good explanation about this calculations on books, I think that R show stress em a percentage data (0-100) and other software in a proportional data (0-1), it is correct? Thanks Ronaldo -- 11ª lei - Você deve conhecer mais de
2013 Jun 22
1
metaMDS Error, Nan similar or negative values
H ello R-experts, I want to do ordination plots using vegan metaMDS. I have a where many cells have zero values. Data structure: X[1:10,1:14] Height.1 Height.2 Height.3 Height.4 Height.5 Height.6 Height.7 Height.8 Height.9 Height.10 Height.11 Height.12 Height.13 D30I1A 46 0 0 0 0 0 0 0 0 0 39 0 98 D30I1B
2011 May 10
3
metaMDS and envfit: Help reading output
Hello R experts, I've used metaMDS to run NMDS on some fish abundance data, and am also working on correlating environmental data to the NMDS coordinates. I'm fairly new to metaMDS and NMDS in general, so I have what are probably some very basic questions. My fish abundance data consists of 66 sites for which up to 20 species of fish were identified and counted. I ran metaMDS on this data
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 Apr 23
1
problem with data for metaMDS analysis please help
am at my wit's end. I am not sure what is wrong with this data matrix. It is sparse because it is a matrix of species, but I have looked at the row totals and column totals and they are positive. rmetaMDS(x.d) Error in if (autotransform && xam > 50) { : missing value where TRUE/FALSE needed What is wrong? And in the future how in God's name do I easily diagnose whatever
2009 Sep 09
2
"predict"-fuction for metaMDS (vegan)
Dear r-Community, Step1: I would like to calculate a NMDS (package vegan, function metaMDS) with species data. Step2: Then I want to plot environmental variables over it, using function envfit. The Problem: One of these environmental variables is cos(EXPOSURE). But for flat releves there is no exposure. The value is missing and I can't call it 0 as 0 stands for east and west. Therefore I
2017 Jun 07
0
An R question
Hi, Check the FAQ 7.31 https://cran.rstudio.com/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f And read the posting guide too... https://www.r-project.org/posting-guide.html HTH, Ivan -- Dr. Ivan Calandra TraCEr, Laboratory for Traceology and Controlled Experiments MONREPOS Archaeological Research Centre and Museum for Human Behavioural Evolution Schloss Monrepos 56567
2011 Nov 24
4
I cannot get species scores to plot with site scores in MDS when I use a distance matrix as input. Problems with NA's?
Hi, First I should note I am relatively new to R so I would appreciate answers that take this into account. I am trying to perform an MDS ordination using the function ?metaMDS? of the ?vegan? package. I want to ordinate species according to a set of functional traits. ?Species? here refers to ?sites? in traditional vegetation analyses while ?traits? here correspond to ?species? in such