simDat19: Simulate data for Chapter 19: Occupancy model

In ASMbook: Functions for the Book "Applied Statistical Modeling for Ecologists"

Simulate data for Chapter 19: Occupancy model

Description

Simulate detection/nondetection data of Chiltern gentians

Usage

simDat19(
  nSites = 150,
  nVisits = 3,
  alpha.occ = 0,
  beta.occ = 2,
  alpha.p = 0,
  beta.p = -3
)

Arguments

nSites	Number of sites
nVisits	Number of replicate visits per site
alpha.occ	Occupancy intercept
beta.occ	Occupancy slope
alpha.p	Detection probability intercept
beta.p	Detection probability slope

Value

A list of simulated data and parameters.

nSites	Number of sites
nVisits	Number replicate visits per site
alpha.occ	Occupancy intercept
beta.occ	Occupancy slope
alpha.p	Detection probability intercept
beta.p	Detection probability slope
humidity	Humidity covariate
occ.prob	Probability of occupancy at each site
z	True occupancy state at each site
true_Nz	True number of occupied sites
lp	Linear predictor for detection
p	Probability of detection at each site
y	Simulated detection/non-detection data
obs_Nz	Observed number of occupied sites

Author(s)

Marc Kéry

Examples

str(dat <- simDat19())             # Implicit default arguments
str(dat <- simDat19(nSites = 150, nVisits = 3, alpha.occ = 0, beta.occ = 2,
  alpha.p = 0, beta.p = -3))       # Explicit default arguments
str(dat <- simDat19(nSites = 500)) # More sites
str(dat <- simDat19(nVisits = 1))  # Single-visit data
str(dat <- simDat19(nVisits = 20)) # 20 visits, will yield cumulative detection prob of about 1
str(dat <- simDat19(alpha.occ = 2))# Much higher occupancy
str(dat <- simDat19(beta.occ = 0)) # No effect of humidity on occupancy
str(dat <- simDat19(beta.p = 3))   # Positive effect of humidity on detection
str(dat <- simDat19(beta.p = 0))   # No effect of humidity on detection

ASMbook documentation built on Sept. 11, 2024, 5:38 p.m.