Simulate single-species occupancy data

Usage

simulate_occu(
  N = 100,
  J = 4,
  n_occ_covs = 2,
  n_det_covs = 1,
  beta_occ = NULL,
  beta_det = NULL,
  n_visit_groups = 0L,
  sigma_visit = 1,
  seed = NULL
)

Arguments

N: Number of sites (default 100).
J: Number of visits (default 4).
n_occ_covs: Number of occupancy covariates (default 2).
n_det_covs: Number of detection covariates (default 1).
beta_occ: Occupancy coefficients (auto-generated if NULL).
beta_det: Detection coefficients (auto-generated if NULL).
n_visit_groups: Number of groups a visit can belong to (an observer, say), each adding an effect to the detection logit of the visits it made. Visits are assigned to groups uniformly at random. 0 (default) simulates no such effect.
sigma_visit: Standard deviation of the per-group detection effects, drawn from N(0, sigma_visit^2).
seed: Random seed.

Value

A list with y, data, and truth. With n_visit_groups > 0 it also carries visits, a data frame with one row per site-visit in site-major order and the factor column visit_group, and truth gains b_visit (the group effects) and sigma_visit.

Examples

sim <- simulate_occu(N = 50, J = 3, seed = 1)
dim(sim$y)

obs <- simulate_occu(N = 50, J = 3, n_visit_groups = 5, seed = 1)
table(obs$visits$visit_group)