logkda {untb}R Documentation

Etienne's K(D,A)

Description

Calculates Etienne's K(D,A)

Usage

logkda(a)
logkda.a11(a)

Arguments

a Count object

Details

Function logkda() calculates K(D,A) using the method appearing in Etienne (2005), supplementary online material. Function logkda.a11 is a direct implementation of formula A11 in Etienne (2005). The formula is

ommitted...see PDF

where overline{s}(n_i,a_i) are Stirling numbers of the first kind (see logS1).

Note

There are two functions here because logkda(), although faster, is based on a non-obvious method. Function logkda.a11() is much slower (especially for large datasets) but the computational method is a direct transcription of formula A11.

The two functions should produce numerically near-identical output.

Author(s)

Robin K. S. Hankin; logkda() is an R transliteration of pari/gp code appearing in Etienne 2005 (supplementary online material) due to Chave.

References

R. S. Etienne 2005. “A New Sampling Formula for Neutral Biodiversity”. Ecology Letters, volume {8}, pp253–260. doi: 10.111/j.1461-0248.2004.00717.x

See Also

etienne,logS1

Examples

a <- count(c(dogs=7,pigs=3,crabs=1,hogs=1,slugs=1))
logkda(a)
logkda.a11(a)

[Package untb version 1.2-5 Index]