Displaying 20 results from an estimated 300 matches similar to: "environmental data as vector in PCA plots"
2010 Nov 17
1
Total inertia in package Vegan?
Dear all at the R-project help list.
I have run into a problem when it comes to getting values for "total inertia" and "R-squared" for my DCA using "decorana" in the package "vegan". I have tried the "goodness" function, but the reply indicates that it does not work with "decorana" class objects. In Canoco one gets the Total inertia in
2004 Mar 29
1
calculate length of gradient ?
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Dear r-help list,
my question is about ordination technics:
2009 Mar 20
1
CCA - manual selection
Hello,
I am trying to obtain f-values for response (independent) variables from a
CCA performed in vegan package, to see which ones of them have
significative influence in my dependent variables (like the manual selection
in canoco), but I can't find any function (or package) that do such a thing.
The dependents variables are species data, and the independents are
ambiental data.
Than you.
2009 Apr 29
0
combine_factor to empty level
ID: T8dfe471e360ac80264c6c
Dear,
I'm using R 2.8.1 with the package reshape version 0.8.2 .
It seems that the combine_factor function has problems with combining levels to
an empty level:
#EXAMPLE WORKING
test<-sample(c(1:10),1000,replace=T)
testf<-factor(test, c(1:10), LETTERS[1:10])
table(testf,exclude=NULL)
testc<-combine_factor(testf, c(1,1,1,1,1,2,2,2,2,2))
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
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,
2011 Sep 09
1
envfit vector labels with ordiplot3d
Hi R experts,
I'm looking for some help with plotting vectors from envfit in vegan, onto a
3d plot using ordiplot3d. So far I have
data.mds <- metaMDS(data, k=3,trace = FALSE)
vect_data<-envfit(data.mds,vegdata[,3:21],choices=1:3,permu=9999)
ordiplot3d(data.mds,envfit=vect_data)
ordixyplot(data.mds,pch=pts,envfit=vect_data)
(my data's not really called data, I thought it might be
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) :
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
2009 Nov 05
1
plot.envfit/move labels
Dear r-helpers!
Jan Thiele asked r-help-list in february, but I could not find an answer to his question. I have the same problem:
While preparing figures of 'envfit' plots with vegan for publication, I ran into a layout problem, that I found no solution for in the literature or the help archive:
The labels of the vectors that indicate correlations of environental variables sometimes
2008 May 22
1
Packfor library-problem downloading
Hello,
I'm a new user to R, and I was trying to install "packfor" in my R console
and I always run into an error.
I tried to search, in in the forum, someone that already might have made the
same question, but all I could find was a general information how to install
libraries in R.
Pass through all that procedure (Package&Data->Package Installer->Local
Source
2013 Apr 24
1
RDA permutest envfit
Dear all,
I did a RDA and when I looked to the signification of the test with permutest, the output was non-significant. But when I used the envfit function, some of the vectors are significant. All the test's conditions are respected. What it means? Is it an error in the script?
Commands and output:
> permutest(rda.ind, perm=999, first=TRUE)
Permutation test for rda
Call:
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.,
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
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
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
2009 Feb 08
0
library vegan - cca - versus CANOCO
Hi R users,
I have two data matrix, one with community data and another with
environmental data. Prior to preform the CCA, I have used PCA to select some
environmental variables and to avoid redundance information. The result is
that I have 4 environmental variables and my community data matrix where,
following bibliography, I have eliminated rare species.
All variables were log-transformed (x+1)
2001 Feb 24
0
Canonical Correspondence Analysis in R
I think i mentioned this in private communication a while back, but in
case anyone else cares:
I have a version of canonical correspondence analysis (CCA) coded up in
R. I based it on
Ter Braak and Prentice (1988) Adv. Ecol. Res. 18:271-317,
Ter Braak (1986) Ecol. 67(5):1167-1179, and
Ter Braak (1995) Section 5.9 in Jongman, Ter Braak, and
van Tongeren "Data Analysis in
2010 Feb 13
2
NMDS ordination
Hi
Im currently trying to plot my NMDS data together with fitted variables
(envfit funct) on an ordination plot. The plot function shows two
displays="sites" and "sp". I was wondering how to plot it so that the sites
come up as different points for different sites but the species come up as
actual names? It looks a little busy at the moment with everything in.
Sya
--
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2011 Dec 20
2
any DCCA function in R?
Dear members,
I am performing multivariate analysis on marine benthic populations
using R. At first glance I found ca and VEGANO packages to be the
suitable for the task, but neither has incorporated Detrended Canonical
Correspondence Analysis (DCCA), which is just the method I want to apply
on my data. I've looked for alternative packages containing the method,
but my suspicion is that