null_dispersion_field_distribution {bamm}

null_dispersion_field_distribution: Null distribution of the dispersion field

Description

null_dispersion_field_distribution estimates a random distribution of the dispersion field values.

Usage

null_dispersion_field_distribution(
  pam,
  n_iter = 10,
  parallel = TRUE,
  n_cores = 2
)

Arguments

pam

A Presence-Absence-Matrix of matrix class or sparse matrix.

n_iter

Number of iterations to obtain the distribution.

parallel

If TRUE the computations will be performed in parallel.

n_cores

Number of cores for the parallel computation.

Details

Estimates a random distribution of the dispersion field values. To obtain random values it uses the function codepermute_pam at each step of the iterations. Randomization of the PAM is performed using the Babe Ruth Algorithm see Strona et al. (2014).

Value

A data matrix of size nrow(pam) X n_iter with dispersion field values.

Author(s)

Luis Osorio-Olvera & Jorge Soberón

References

Soberon J, Cavner J (2015). “Indices of Biodiversity Pattern Based on Presence-Absence Matrices: A GIS Implementation.” Biodiversity Informatics, 10, 22–34.

Strona G, Nappo D, Boccacci F, Fattorini S, San-Miguel-Ayanz J (2014). “A fast and unbiased procedure to randomize ecological binary matrices with fixed row and column totals.” Nature Communications, 5(1), 1–9. ISSN 20411723, doi:10.1038/ncomms5114, https://www.r-project.org.

Examples

set.seed(111)
pam <- matrix(rbinom(100,1,0.3),nrow = 10,ncol = 10)
dfield_rand <- bamm::null_dispersion_field_distribution(pam,n_iter=10,
                                                       parallel=FALSE,
                                                       n_cores = 2)
head(dfield_rand)