Re: [R-sig-eco] envfit function: is it possible to display correlation coefficient?

2018-05-02 Thread syrovat
Dear all, Just to expand the reply by Zoltan. NMDS1 and NMDS2 in the envfit() output are the positions of heads of arrows of unit length. They show the direction of the "best" linear fit into the n-dimensional solution of the ordination. The r2 then says how good the fit is. I.e. it refers to

Re: [R-sig-eco] Reordering dendogram

2017-10-11 Thread syrovat
(Sorry for double-posting, the original message does not seem to appear in the forum.) "Everything" seems to be possible with the dendextend package. Check its extensive vignette at CRAN. Vit Dne 2017-10-10 14:54, Tania Bird napsal: I am trying to control the order and colour of a

Re: [R-sig-eco] Reordering dendogram

2017-10-11 Thread syrovat
"Everything" seems to be possible with the dendextend package. Check its extensive vignette at CRAN. Vit Dne 2017-10-10 16:01, Clifford Beall napsal: Try the reorder function, the dendrogram specific help is at ?reorder.dendrogram. I’m not sure about the symbols on the labels though. On Oct

Re: [R-sig-eco] biplot with most important species

2016-10-12 Thread syrovat
Hi Bjorn, A common practice in simplifying ordinatin plots is to keep species that show the best fit into the ordination space. The position of such species in the ordination diagram really (may) tell something. In linear methods like PCA a linear fit is suitable. This can be computed using

Re: [R-sig-eco] Difference between mantel test and adonis

2013-01-17 Thread syrovat
Thank you very much for your explanations. So if I understood it correctly, a significant outcome from adonis() (or capscale()) should indicate me that my species community changes along the gradient? Yes, you understand it correctly. Nice that you also mention betadisper, because I'd like

Re: [R-sig-eco] Difference between mantel test and adonis

2013-01-16 Thread syrovat
Hi Valérie, adonis is analogous to RDA or CCA, as it directly estimates the variance in the distance matrix attributable to an independent variables(s), with the advantage that one may use any distance measure. It parallels r2 in a linear model. Mantel test simply calculates the correlation

Re: [R-sig-eco] adonis: error in rowSums

2012-02-09 Thread syrovat
Dear Caroline, It seems that you response (community-like) data are Depth and Velocity. Than a dataframe with these two variables should be on the left hand side of the formula, while SFT on the right hand side. Something like adonis(LB[,2:3] ~ SFT, data=LB, method=canberra) should work. Cheers,

Re: [R-sig-eco] Is MAFA and DFA implemented in R?

2011-01-14 Thread syrovat
Hi Roman, Thank you. My question should be rather if something has changed since then. The web page of the book by Alain F. Zuur (chapter 17 and 33) is exactly where I was looking for the R code. Cheers, Vit This is from the highstat website on DFA (Analyzing ecological

Re: [R-sig-eco] change values of a vector selectively

2011-01-11 Thread syrovat
Hi Mango, If I understand it well, the following loop should do the work. I include a small example. a- c(1,0,0,0,'A',0,0,0,2,0,0,0,1,0,0,0,0,2,0,0,0,1) for(i in (1:length(a)-1)){ if (a[i+1]==0) a[i+1]-a[i]} a [1] 1 1 1 1 A A A A 2 2 2 2 1 1 1 1 1 2 2 2 2 1 Cheers, Vit -- Vit Syrovatka

[R-sig-eco] ADONIS and pseudoreplications

2010-11-10 Thread syrovat
Dear listers, I intended to send a separate question but it fell under comments on Eduard Szöcs's question. Sorry for that. The problem: I collected aquatic insect larvae from 17 sites three times (spring, summer, autumn), giving a total of 51 samples. During each sampling campaign several

Re: [R-sig-eco] Species fit in ordination

2010-07-31 Thread syrovat
My apologies for sending my reply to Jari Oksanen only. See it below, please. Vit Dear Jari Oksanen, Thank you for your suggestions! You really have to define what is a good fit. Having a large change in probability is different from explaining a large part of the variation of observations.