Re: [R-sig-eco] Diversity on standardised densities in R

2013-10-25 Thread Vít Syrovátka
Hi, vegan::rrarefy() is the right way to do this. However, I can't imagine, how to take 50 random individuals from a sample with less then 50 individuals. One doesn't know, what species would be collected in case of a larger sampling effort, R doesn't know either. I would suggest doing this on

Re: [R-sig-eco] Diversity on standardised densities in R

2013-10-25 Thread Mario José Marques
Hi Paris, excuse-me if I do not understand you. I think that or you standardize you effort to less individual in your samples or you extrapolation your sample to that more abundant. If you have sample with less individual, like you say, it is not recomended to do extrapolation. If your accum

Re: [R-sig-eco] Diversity on standardised densities in R

2013-10-25 Thread Peter Solymos
Hello, A parametric model (e.g. Clench) would allow both intrapolation and extrapolation. There are some caveats of course: (1) these models arose in the temporal accumulation sense, spatial accumulation is usually calculated for randomized data, which is an assumption that individuals in the samp

Re: [R-sig-eco] Missing species names in metaMDS object

2013-10-25 Thread Gavin Simpson
As your output *clearly* tells you, `spp_sites_mat` is a *list*: str(spp_sites_mat) List of 186 < HERE! $ ADON.CUPA: num [1:450] 0 0 0 0 0 0 0 0 0 0 ... $ AEGI.GENI: num [1:450] 0 0 0 0 0 1 1 0 1 0 ... $ AINS.