asim10: Resampling with row/column abundances fixed

In irhoppe/cooccur: Abundance Matrix Randomizations

Description

Randomizes an abundance matrix by assigning individuals to matrix cells with probabilities proportional to observed row and column abundance totals until, for each row and column, total abundances are reached.

Usage

asim10(speciesData)

Arguments

speciesData

species-by-site abundance matrix

Details

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

Preserves species and site abundances, but allows occurrences to vary.

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(), asim11_f(), 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
asim10(amat)        # performs proportional abundance resampling algorithm

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