Jari,

Indeed you right. I think is like you said.
Thank you so much,


-- 
Gian


2012/3/30 Jari Oksanen <jari.oksanen@oulu.fi>

> I think the difference is like documented. Citing your own message:
>
> ""all" calculates the diversity of the entire
> community (all sites pooled), ..., "mean" calculates the average diversity
> of the sites"
>
> So "all" uses pooled data (colSums(<data>)), and "mean" uses non-pooled
> data but calculates the average of results. That is, it first calculates
> the diversities (as with method = "s"), and then takes their average.
>
> Cheers, Jari Oksanen
> ________________________________________
> From: r-sig-ecology-bounces@r-project.org [
> r-sig-ecology-bounces@r-project.org] on behalf of Gian Maria Niccolò
> Benucci [gian.benucci@gmail.com]
> Sent: 30 March 2012 11:57
> To: r-sig-ecology@r-project.org
> Subject: [R-sig-eco] diversityresult function - BiodiversityR package
>
> Hi all,
>
> I would compare the diversity of two groups of samples through the use of
> diversity indices such as richness, shannon, simpson, evennes etc.
> I then used the diversityresult() to calculate such indices. Once I got
> diversity for each sample and tested for data normality I used simple ANOVA
> to evaluate differences between such groups.
>
> -Do this apprach be correct?
>
> Moreover, in the help of the function is written: "Method of calculating
> the diversity statistics: "all" calculates the diversity of the entire
> community (all sites pooled), "s" calculates the diversity of each site
> separatedly, "mean" calculates the average diversity of the sites, "sd"
> calculates the standard deviation of the diversity of the sites"
>
> - What is the differenc in calculation between "all" and "mean" methods?
> maybe "all" first pools sites and then calculate diversity while "mean"
> first average the sites and then calculate diversity?
>
> Thanks a lot for replies,
>
> --
> Gian
>
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>
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