[R] Brillouin index

[MacQueen, Don]

It's a pretty simple formula, according to the sources I found.

Here's a function that looks right to me, but I have no independent
calculation with which to check it.
(no guarantees!)

Hb <- function(ns) {
  N <- sum(ns)
  (lfactorial(N) - sum(lfactorial(ns)))/N
}

> ns <- c(3,5,2,8)
> Hb(ns)
[1] 1.028802




-- 
Don MacQueen

Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062





On 1/13/12 8:12 AM, "Philipp Fischer" <Philipp.Fischer at awi.de> wrote:

>Dear colleagues.
>
>I wonder if anybody knows about a procedure in R to calculate the
>Brillouin Diversity index.
>
>I searched the net but did not find anything about it.
>
>Thanks a lot for any help
>
>Best, Philipp
>***************************************************
>Prof. Dr. Philipp Fischer
>Head of AWI Center for Scientific Diving & Dept. In situ Ecology
>Section Shelf Sea Systems
>Alfred-Wegener-Institut
>Biologische Anstalt Helgoland
>Building A
>D-27498 Helgoland
> 
>Phone: +49(4725)819-3344
>Skype: fischer_philipp
>Fax: +49(4725)819-3369
> 
>http://www.awi.de/People/show?pfischer
>http://www.awi.de/en/infrastructure/underwater/scientific_diving/
>http://www.awi.de/en/research/research_divisions/biosciences/shelf_sea_eco
>logy/
>http://www.forschungstauchen-deutschland.de
>
>
>
>
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