asim11_f: Resampling species by species with row abundances fixed

In irhoppe/cooccur: Abundance Matrix Randomizations

Description

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

Usage

asim11_f(speciesData)

Arguments

speciesData

species-by-site abundance matrix

Details

Resamples species abundances conditional on column sums and constrained to observed row abundance; equivalent to algorithm ITR in Ulrich and Gotelli (2010), and to the Fortran subroutine itr 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(), asim12_f(), asim12(), 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
asim11_f(amat)      # performs proportional abundance resampling algorithm

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