Dear Jari,


I did the calculation again and now it clearly make more sense. Otherwise I
do not have clear what do you mean with "
the step length is relative to the proportional decrease in the number of
classes". If I do not understand bad in the paper of Clark and Warwick
(1999) they say that steps lenght is proportional to the percentage
decrease in richness from taxon k to taxon k+1 (so is the taxon richnes
that vary from e.g. genus to order and from order to familny and so on). So
the number of classes is the taxon richness, Am I right?
Thanl you very much for help and patience,

Gian




2012/2/23 Jari Oksanen <jari.oksanen@oulu.fi>

>
> 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@oulu.fi, Ph. +358 400 408593, http://cc.oulu.fi/~jarioksa
>
>
>
>

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