Yes ! Perfect.
Le 06/06/2019 à 17:17, Tim Richter-Heitmann a écrit :
Hi Stephane,
thank you for this very useful information.
As for the global test, the tutorial of Benoit Gendreau-Berthiaume (as
linked in my mail) does start the analysis with anova.cca on a RDA
fitting all available dbMEM before doing variable selection.
Does this satisfy the requirement of a global test?
Cheers, Tim
Am 06.06.2019 um 17:03 schrieb Stéphane Dray:
Hi,
we introduced a new function mem.select in adespatial (that used
forward.sel) based on the work by Bauman et al
(https://onlinelibrary.wiley.com/doi/abs/10.1111/ecog.03380)
Basically, we showed that you should use a global test before
performing forward selection (this step is suggested by Blanchet et al
but rarely performed in ecological studies).
Cheers
Le 06/06/2019 à 16:41, Tim Richter-Heitmann a écrit :
Dear Irene,
i found this tutorial very useful:
https://sites.ualberta.ca/~ahamann/teaching/renr690/Lab9.pdf
You basically do a forward selection (forward.sel() from packfor
package) using the adjusted R-square (RsquareAdj() from vegan package).
Hope this helps, Tim
Am 06.06.2019 um 16:34 schrieb Irene Adamo:
Dear all,
I am trying to run a variaion partitioning in using the varpart
function in
vegan. I would like to include the geographic coordinates as
explanatory
variables so I calculated the principle coordinates of neighbour
matrices.
Now I would like to perform a selection of the significant spatial
eigenvectors but I don`t know how to do it in R. Could anybody help me?
data(mite.xy)
pcnm1 <- pcnm(dist(mite.xy))
then I get the pcnm vectors and I would like to select only the
significant ones.
Thanks a lot!
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Stéphane DRAY (stephane.d...@univ-lyon1.fr)
Laboratoire BBE-CNRS-UMR-5558, Univ. C. Bernard - Lyon I
43, Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
http://pbil.univ-lyon1.fr/members/dray/
GdR EcoStat : https://sites.google.com/site/gdrecostat/
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