asim12: Resampling site by site with column abundances fixed

In irhoppe/cooccur: Abundance Matrix Randomizations

Description

Randomizes an abundance matrix by sequentially (column after column) assigning individuals to each column with probabilities proportional to observed row abundance totals until the respective total column abundance is reached.

Usage

asim12(speciesData)

Arguments

speciesData

species-by-site abundance matrix

Details

Resamples species abundances conditional on row sums and constrained to observed column abundance; equivalent to algorithm ITC in Ulrich and Gotelli (2010), and to the Fortran subroutine itc in Ulrich (2008).

Value

shuffled abundance matrix

References

Ulrich, W. 2008. Program Co-Occurrence. Version 1.

Ulrich, W. and Gotelli, N.J. 2010. Null model analysis of species associations using abundance data. Ecology 91:3384-3397.

See Also

Other abundance matrix null models: asim10_f(), asim10(), asim11_f(), asim11(), asim12_f(), asim13_f(), asim13(), asim14_f(), asim14(), asim1_f(), asim1(), asim2_f(), asim2(), asim3_f(), asim3(), asim4_f(), asim4(), asim5_f(), asim5(), asim6_f(), asim6(), asim7_f(), asim7(), asim8_f(), asim8(), asim9_f(), asim9()

Examples

amat <- rmat(20,12) # creates a random 20 x 12 abundance matrix
asim12(amat)        # performs proportional abundance resampling algorithm

irhoppe/cooccur documentation built on Jan. 1, 2021, 4:23 a.m.