create_octaves: Reclassify a vector of species' abundances into abundance octaves
Description
Creates abundance octaves by a log2 transform that doubles the number
of abundance classes within each octave (method 3 of Gray, Bjoergesaeter & Ugland 2006).
Octave 0 contains the number of species with 1 individual, octave 1 the number of species
with 2 or 3 individuals, octave 2 the number of species with 4 to 7 individuals, and so forth.
Usage
create_octaves(abundances, subsample = 0)
Arguments
abundances
A numerical vector of species abundances in a community.
subsample
If > 0, the community is subsampled by this number of individuals before creating octaves. This is useful for analyses where alpha is estimated from a standardized number of individuals.
Value
A data.frame with two variables: octave with the name of each octave and species with
the number of species in that octave.
References
Gray, J.S., Bjoergesaeter, A. & Ugland, K.I. (2006) On plotting species abundance distributions. Journal of Animal Ecology, 75, 752-756.