search for: trymax

Displaying 13 results from an estimated 13 matches for "trymax".

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2006 Nov 10
2
Problems with metaMDS from vegan
...n both machines. On the new Ubuntu machine I even tried to regress to the Vegan 1.6-10, but to no avail, as the error remains the same: As soon as a I try to process an R matrix (see below) to obtain the MDS I am confronted with: > meta <- metaMDS(distab.dist, distance="bray", k, trymax=50) Fehler in rowSums(x, na.rm = TRUE) : 'x' muss ein Array mit mindestens zwei Dimensionen sein Ausf?hrung angehalten ( translated: error in rowSums(x, a.rm = TRUE) : 'x' must be an array of at least two dimensions. Execution stopped ) This error is not appearing on identical dat...
2010 Dec 01
1
procrustes results affected by order of sites in input file
...rocrustes 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") invert.mds<-metaMDS(bugcal.a, distance="bray", k=3, trymax=100, wascores=TRUE, trace=TRUE, zero="add"), where fish.data and invert.data are site-by-abundance matrices for fish and invertebrates, respectively. I have th...
2011 Sep 23
1
Envfit, inconsistant result?
...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, 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...
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 iso...
2011 May 10
3
metaMDS and envfit: Help reading output
...rent dimensions). I then used envfit to correlate a predictor dataset of environmental variables with the NMDS results, using the following code. >Fish<-as.data.frame(read.csv("Fish.csv",header=TRUE, sep = ",")) >Fish.mds<-metaMDS(Fish,zerodist = "add",k=3,trymax=20) >Predictors<-as.data.frame(read.csv("Predictors.csv",header=TRUE, sep = ",")) >Fish.fit <- envfit(Fish.mds$points, Predictors, k=3, 1000, na.rm = TRUE) >Fish.fit The output of Fish.fit was as follows (table truncated): Dim1...
2013 Apr 26
1
NMDS in Vegan: problems in stressplot, best solution
...not I define both line and point at the same time? If I have 100 iterations for metaMDS, then when I plot the result, does it give me result from best solution? How do I know that. Can you plot the Stress by Iteration number? parth.mds <- metaMDS(WorldPRSenv, distance = "bray", k = 2, trymax = 100, engine = c("monoMDS", "isoMDS"), autotransform =TRUE, wascores = TRUE, expand = TRUE, trace = 2) plot(parth.mds, type = "p") Thanks in advance, Kumar -- Section of Integrative Biology University of Texas at Austin Austin, Texas 78712, USA [[alternative HTM...
2012 Jul 27
1
labeling loading vectors in vegan
...ld like to suppress the labels for the loading vectors. Is this possible? Alternatively, how can I avoid overlap? Many thanks for the help. Example code: #perform NMDS using metaMDS() function spe.nmds<-metaMDS(data, distance='bray',k=2 , engine = "isoMDS", autotransform=F, trymax=1000) #calculate the loading (i.e., variable weights) on each NMDS axis vec.sp<-envfit(spe.nmds$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="Axis 2"...
2013 Sep 06
1
Fwd: calculating dissimilarity index of islands (vegan and betapart)
...compare species presence/absence between a pair of island? Should the two islands be specifically located or close to each other?) Thank you Elaine Code # NMDS library(MASS) library(vegan) island.NMDS <- metaMDS(island,k=2, distfun = betadiver, distance = "sim",trymax=100,zerodist="add") plot(island.NMDS, type = "n") #Simpson Dissimilarity Index library(betapart) island.dist<-beta.pair(island, index.family="sor") class(island.dist) [[alternative HTML version deleted]]
2010 Jan 06
1
positive log likelihood and BIC values from mCLUST analysis
...ues of BIC and 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...
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 is...
2011 May 22
0
Manipulating rownames for nMDS
...D.1 0 0 0 0 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 t...
2011 Mar 10
1
3 dimensional MDS plots
...n 3 stress 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....
2010 May 25
2
Calculation time of isoMDS and the optimal number of dimensions
Dear all, I'm running a set of nonparametric MDS analyses, using a wrapper for isoMDS, on a 800x800 distance matrix. I noticed that setting the parameter k to larger numbers seriously increases the calculation time. Actually, with k=10 it calculates already longer than for k=2 and k=5 together. It's now calculating for 6 hours, and counting... There is quite a difference between the