similar to: NMDS ordination

Displaying 20 results from an estimated 700 matches similar to: "NMDS ordination"

2011 Sep 23
1
Envfit, inconsistant result?
Hi R-experts, I am using the envfit function over an ordination of floristic data. The problem is that every time that I run it changes the results. Sometimes dramatically, selecting variables that the first time were not significant. I do not get what could be the problem or if is normal given the permutations are different. # the NMDS ordination gap_flor_NMDS_chord <- metaMDS(gaps_flor,
2012 May 09
1
reception of (Vegan) envfit analysis by manuscript reviewers
I'm getting lots of grief from reviewers about figures generated with the envfit function in the Vegan package. Has anyone else struggled to effectively explain this analysis? If so, can you share any helpful tips? The most recent comment I've gotten back: "What this shows is which NMDS axis separates the communities, not the relationship between the edaphic factor and the
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
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.,
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
2012 Dec 29
2
Error in plot.envfit(ef, p.max = 0.1) : (subscript) logical subscript too long
Hello there, I'm trying to plot vectors with p<0.1 in a NMDS ordination plot using p.max. Below the scripts I'm using. I guess I'm missing something! could you please give me a hand? species<-metaMDS(species_matrix)ef<-envfit(species,environmentaldata_file,permu=999,na.rm=TRUE)efplot(species, dis="sites")plot(ef,p.max=0.1) Error in plot.envfit(ef, p.max = 0.1) :
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
2011 Mar 28
1
ordination in vegan
Hi all, I have site data with plant species cover and am looking for trends. I'm kind of new to this, but have done lots of reading and can't find an answer. I tried decorana (I know it's been replaced by ca.) and see a trend, but I'm not sure what it means. Is there a way to get the loadings/eigenvectors of the axes (like in PCA)? Is there a way to do this with rda() too? How
2010 Apr 13
1
vegan (ordisurf): R² for smoothed surfaces
Dear r-helpers, I just read in an article by Virtanen et al. (2006) where vegetation-environment relationships are studied by fitting smoothed surfaces on an NMDS ordination using GAMs (Wood 2000). The authors describe, that they used R? as goodness-of-fit statistic, which they compare to the R? of fitted vectors. Calculations were carried out using the package vegan (Oksanen). I know that I can
2010 Apr 04
3
How to split data for NMDS plots
I have a data matrix that contains site data for paired infested and control plots. For example: ab ac ad af ag ah 1 .024 x x x x x 2 .9 x x x x x 3 1.5 x x x x x 4 2.3 x x x x x 5 1.0 x x x x x 1c .75 x x x x x 2c 2.1 x x x x x 3c 1.7 x x x x x 4c 10.2 x x x x
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
2010 Dec 08
1
on NMDS graphics
Hi, I have used Vegan to construct an NMDS ordination plot. I plotted sites of three forest types with the site number in it. My reviewer has asked me to use different symbols for each of the forest types. Can anyone send me how I can do this in R in simple steps. I have used the options like ordiplot, sel and pl syntaxes that are not working for the question that I asked for. Best, Sinu --
2013 Apr 11
1
Ordination Plotting: Warning: Species scores not available
Hi, I am working with a species-by-trait .csv file (columns=traits, rows=species) and get the following warning message when trying to plot results of both metaMDS and pcoa:  "Warning message: In ordiplot(x, choices = choices, type = type, display = display,  :   Species scores not available" I am using a Gower's transformation in both procedures within the metaMDS or pcoa
2010 Apr 07
1
Customizing ordination plots using symbols for factors
Hi, I could use a hand solving a fairly straightforward ordination plot problem: I am conducing NMDS on some community data for roughly 300 localities and 650 species. I have a community matrix, a species attribute matrix, and an environmental attributes matrix. After running metaMDS {vegan} on the community matrix, I can successfully use either of the other two matrices to draw hulls around
2007 Nov 14
1
label plotting on nmds diagram
Hi, I'm using nmds command (library vegan) to analyze some fishing data. I'd like to plot not only points, but also the names of species and stations in a specified position. I used the command text(nmds$points[,1], nmds $points[,2],labels=row.names(nmds $points),pos=3,cex=0.5) But the labels are sometimes overlapped. Is there any way to use identify, or a similar command, to plot the
2018 Apr 17
2
nMDS with R: missing values
Dear All, I was wondering whether anyone might be able to provide some advice with an nMDS / R problem. I?m trying to run nMDS on a dataset that contains many missing values and was wondering how I can account for the missing values when running nMDS? It seems as though the data are being grouped depending on where the zero values appear. Any suggestions greatly appreciated. Thank you very much
2008 Sep 09
2
NMDS and varimax rotation
hello, subsequently to a NMDS analysis (performed with metaMDS or isoMDS) is it possible to rotate the axis through a varimax-rotation? Thanks in advance. Bernd Panassiti
2010 Jan 20
1
Problem in NMDS
Hi, I am stuck in one problem when doing nonmetric multidimensional scaling. I use the function 'metaMDS' in the package 'vegan' to work on the presence/absence community data. The problem is when two samples are identical (dissimilarity = 0), metaMDS cannot work with zero dissimilarity. I don't want to delete the duplicates as they are true samples from different locations.
2011 Sep 09
2
NMDS plot and Adonis (PerMANOVA) of community composition with presence absence and relative intensity
Hi! Thanks for providing great help in R-related statistics. Now, however I'm stuck. I'm not a statistics person but I was recommended to use R to perform a nmds plot and PerMANOVA of my dataset. Sample(treatment) in the columns and species (OTU) in the rows. I have 4 treatments (Ambient Temperature, Ambient temperature+Low pH, High temperature, High temperature+low pH), and I have 16
2012 May 10
1
envfit output (vegan package) - not sure what it means
I'm pretty new to R and would appreciate some help interpreting the output of a function that was recommended to me. I've used the *envfit *function in the vegan package to plot vectors of four climate variables onto a species matrix ordination. The output indicates that only a single variable (mean_temp) is significant: ***VECTORS NMDS1 NMDS2 r2