[R-sig-eco] taxonomic diversity and distinctness - taxondive() in vegan package

[Jari Oksanen]

On 21/02/2012, at 13:38 PM, Gian Maria Niccolò Benucci wrote:

> Dear All,
> 
> I just want to ask if someone can explane me how the steps are calculated
> in taxa2dist().
> I would know how steps are calculated because it is foundamental to define
> the weights [I'm referring to Clarke & Warwick (1999)] given to taxonomic
> relationships. Why I do have the same step value for genus and class ranks?
> Below is reported the code.

When I implemented step lengths, I followed Clarke & Warwick (1999): probably they explain the scaling, and I would read that reference if I needed to explain how it works.

The docs say that the step length is relative to proportional decrease in the number of classes. Does this apply to your genus and class ranks?

Cheers, Jari Oksanen
-- 
Jari Oksanen, Dept Biology, Univ Oulu, 90014 Finland
jari.oksanen at oulu.fi, Ph. +358 400 408593, http://cc.oulu.fi/~jarioksa