Displaying 15 results from an estimated 15 matches for "autotransform".
Did you mean:
aug_transform
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.
cd<-dist(cm...
2011 Sep 23
1
Envfit, inconsistant result?
...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, distance = "euclid", k = 2, trymax
= 20, autotransform =TRUE,
noshare = 0.1, wascores = TRUE, expand = TRUE, trace = 1,
plot = FALSE, old.wa = FALSE, zerodist = "add")
# the environmental variables to use with enfit
explain1<- site[c("Tipo", "Gap.size", "Gap diameter (m)", "Size.cat",
"altitu...
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 problem there is with this data. I am in debt to anyone who
figures this one out.
Thanks
Stephen
-------------- next part --------------
An embed...
2013 Apr 26
1
NMDS in Vegan: problems in stressplot, best solution
...erations for metaMDS, then when I plot the result, does it
give me result from best solution? How do I know that. Can you plot the
Stress by Iteration number?
parth.mds <- metaMDS(WorldPRSenv, distance = "bray", k = 2, trymax = 100,
engine = c("monoMDS", "isoMDS"),
autotransform =TRUE, wascores = TRUE, expand = TRUE, trace = 2)
plot(parth.mds, type = "p")
Thanks in advance,
Kumar
--
Section of Integrative Biology
University of Texas at Austin
Austin, Texas 78712, USA
[[alternative HTML version deleted]]
2013 Feb 27
1
best ordination method for binary variables
....
The problem is that, when trying this methods, I immediately get problems
due to the identity between several of mycases or the presence of NA.
Typical error messages are
*"Error in isoMDS(DistB, k = 3) : zero or negative distance between objects
1 and 2"*
or
*"Error in if (any(autotransform, noshare > 0, wascores) && any(comm < 0))
{ : missing value where TRUE/FALSE needed*
*In addition: Warning message:*
*In Ops.factor(left, right) : < not meaningful for factor"*
Do you think Principal coordinate analysis on a binary distance matrix is a
decent strategy?
Thank...
2012 Jul 27
1
labeling loading vectors in vegan
...DS 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., variable weights) on each NMDS axis
vec.sp<-envfit(spe.nmds$points, data, perm=1000, choices=c(1:2))
#plot data in ordination
ordiplot(spe.nmds, choices=c(1:2), type='text', display="sites", xlab="Axis
1", ylab="Ax...
2013 May 27
1
metaMDS with large dataset produces 'insufficient data' warning
...educed 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 metaMDS(MDSdata, distance = "bray", k = 2, autotransform = FALSE) :
Stress is (nearly) zero - you may have insufficient data
I don't think I have insufficient data, with 12 x 25071 data points, and when I reduce the dataset to only 1000 values per model run (so only 12 x 1000) I don't get this warning (though the final stress is now only just...
2007 Aug 24
1
Adding new points to a metaMDS ordination ("vegan" pkg)
...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 metric here. It gives me a great
ordination that appears to represent my ecological gradients well. What
I want to do is passively add new points to the ordination in an effort
to "predict" visually certain ecological attributes.
I have tr...
2010 Jan 06
1
positive log likelihood and BIC values from mCLUST analysis
...d log
likelihood. The relevant part of my R script is:
######################### BEGIN MDS ANALYSIS #########################
#load data
data <- read.table("Ecoli33_Barry.dis", header = TRUE, row.names = 1)
#perform MDS Scaling
mds <- metaMDS(data, k = Dimensions, trymax = 20, autotransform =TRUE,
noshare = 0.1, wascores = TRUE, expand = TRUE, trace = FALSE, plot = FALSE,
old.wa = FALSE)
######################### BEGIN EM ANALYSIS #########################
#Use the points determined by MDS to perform EM clustering.
#Allow only the unconstrained models. Sometimes, constrained models...
2011 Sep 09
2
NMDS plot and Adonis (PerMANOVA) of community composition with presence absence and relative intensity
...as?
#NMDS
step1<-read.delim2("day20.txt", row.names=1)
library(clusterSim)
step2<-data.Normalization(step1,type="n10")
step3<-asin(sqrt(step2))*57.3
step4<-t(step3)
library(vegan)
step5<-data.matrix(vegdist(step4,method="bray"))
step6<-metaMDS(step5, autotransform=FALSE)
plot(step5)
Warning message:
In ordiplot(x, choices = choices, type = type, display = display, :
Species scores not available
#PerMANOVA
step1<-read.delim2("day20.txt", row.names=1)
library(clusterSim)
step2<-data.Normalization(step1,type="n10")
step3<-asin(...
2008 Apr 23
0
Problem with Species x Site matrix please help
I 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.
metaMDS(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 problem there is with this data. I am in debt to anyone who
figures this one out.
Thanks
Stephen
--
Let's not spend our time and resources...
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.
cd<-dist(c...
2011 May 22
0
Manipulating rownames for nMDS
...ST9_MF..CC.3 1 0 0 1
ST9_MF..CC.4 1 0 0 1
FX9_MF..CH.1 1 1 0 0
FX9_MF..CH.2 1 0 0 0
This is the code I have thus far:
datum <- read.csv(q, header=F)
datum2 <- datum[,2:ncol(datum)]
rownames(datum2) <- datum[,1]
fit <- metaMDS(datum2, distance = "jaccard", k = 3, trymax=20,
autotransform=F)
fit. <- data.frame(sample=rownames(datum2), fit$points)
p <- qplot(X1,X2, col=sample, data=fit.)
print(p)
dev.off()
Thanks for your help!
--
View this message in context: http://r.789695.n4.nabble.com/Manipulating-rownames-for-nMDS-tp3542663p3542663.html
Sent from the R help mailing...
2011 Mar 10
1
3 dimensional MDS plots
...10.61520
... New best solution
... procrustes: rmse 0.005646588 max resid 0.009332332
Run 4 stress 10.61520
... New best solution
... procrustes: rmse 0.0001009763 max resid 0.0001754211
*** Solution reached
> mdsg.mds.ALT<- metaMDS(mdsg, distance="euclidean", k=3, trymax=50, autotransform=FALSE)
Run 0 stress 3.020817
Run 1 stress 0.00673153
... New best solution
... procrustes: rmse 0.09349157 max resid 0.2443702
Run 2 stress 0.008861757
... procrustes: rmse 0.08275172 max resid 0.1932439
Run 3 stress 0.006908548
... procrustes: rmse 0.0447681 max resid 0.1093436
Run 4 str...
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