[R-sig-Geo] Is it possible to merge togheter different ENFA results?

Mathieu Basille basille.web at ase-research.org
Tue Jun 25 20:55:26 CEST 2013

Dear Michela,

I'm not quite sure to understand what you really intend to do. I can see 
that you performed individual ENFAs for each of your study site. This is 
fair, although you might be interested in the OMI for that multi-niche 
comparison (see ?niche in package ade4, and reference [1]).

But now, you want to perform a MADIFA on top of this? It does not make 
sense to me... Here, I'm really not sure what you want to do.

Finally, a single analysis for the 3 sites at once might also make sense, 
and this is largely feasible with R. It will need a little bit of tweaking 
though. All you have to do is to combine the results after the extraction 
of the environmental characteristics and the vector of presence (before the 

Hope this helps,
Mathieu Basille.

[1] Doledec, S.; Chessel, D. & Gimaret Carpentier, C. (2000) Niche 
separation in community analysis: A new method. Ecology, 81: 2914-2927 doi 

Le 06/25/2013 05:36 AM, Michela Giusti a écrit :
> Hello everybody ,
> I have a question regarding ENFA process.
> I have 3 sites far from one another along the Mediterranean Sea.
> I performed 3 different ENFA (one for each site; the species is the same
> for each site).
> Now I would like to merge togheter the 3 ENFA results to have the final
> result and to perform the final MADIFA on it.
> Is it possible to do that? I tryed also to do a single ENFA on the 3 sites
> from the beginning of my analysis , but I had problems with the extents of
> the rasters.
> Thank you very much for your help.
> Bye,
> Michela


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Mathieu Basille, PhD

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