Displaying 20 results from an estimated 1000 matches similar to: "vegan metaMDS question"
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
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 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
2009 Jan 21
1
vegan metaMDS
Hi,
I'm trying to use metaMDS with a dissimilarity matrix of angles, not
Bray-Curtis, and I wanted to know if there is an in-built function to
produce a plot of stress values against dimensions, that could be used to
determine the 'true' dimension of the solution. The number of objects is
only a lowly 8 so any solution higher than 2-dimensional is not likely to be
interpretable,
2010 Dec 01
1
procrustes results affected by order of sites in input file
Dear All,
I am using a Procrustes analysis to compare two NMDS ordinations for the
same set of sites. One ordination is based on fish data, the other is based
on invertebrate data. Ordinations were derived using metaMDS() from the
{vegan} library as follows:
fish.mds<-metaMDS(fish.data, distance="bray", k=3, trymax=100,
wascores=TRUE, trace=TRUE, zero="add")
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 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
2010 Apr 05
4
NMDS Ordination Graphics Problem
Dr. Stevens,
Hi, my name is Trey Scott, and I'm a grad student of Brian McCarthy's. He
referred me to you because of your expertise in handling complex R problems.
We were hoping you could help us solve a nagging problem that is prohibiting
me from producing graphicl output.
Here is a simple mock-up of the matrix I'm using
a b c d e f
1i 1 4
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") :
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
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
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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
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2013 Apr 26
1
NMDS in Vegan: problems in stressplot, best solution
Hello,
I can draw a basic stress plot for NMDS with the following code in package
Vegan.
> stressplot(parth.mds, parth.dis)
When I try to specify the line and point types, it gives me error message.
> stressplot(parth.mds, parth.dis, pch=1, p.col="gray", lwd=2, l.col="red")
Error in plot.xy(xy, type, ...) : invalid plot type
In the above code, if I removed line type,
2012 Jul 27
1
labeling loading vectors in vegan
Hello,
I am using vegan to do an NMDS plot and I would like to suppress the labels
for the loading vectors. Is this possible? Alternatively, how can I avoid
overlap?
Many thanks for the help.
Example code:
#perform NMDS using metaMDS() function
spe.nmds<-metaMDS(data, distance='bray',k=2 , engine = "isoMDS",
autotransform=F, trymax=1000)
#calculate the loading (i.e.,
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
2008 Apr 11
1
Vegan plotting- color help
I have looked all over the internet for being able to color sites
differently in a plot of an MDS (metaMDS)- I would like to color the
different sites in the ordination plot (plot or ordiplot). I have set
the matrix up so that my site code is 1 .... 296 (first column). is
there a way to make 1-23 blue, 24-40 red etc.
thanks
Stephen
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Let's not spend our time and resources thinking
2013 Sep 06
1
Fwd: calculating dissimilarity index of islands (vegan and betapart)
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
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
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2013 May 17
1
Problem with ordiellipse coloured factor in Vegan
Hello R experts,
I am trying to plot ordiellipse for my data but the col according to
factors.
Metabolites_raw= read.csv(file.choose(), head = TRUE) #file
21Metabolites.csv
Metabolites_t=t(Metabolites_raw[,2:82])
ord <- metaMDS(Metabolites_t, distance="bray")
symbol=as.numeric(Metab_metadata$LandType)
col.list <-
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