simPdata: Simulate non-hierarchical point transect (= point count) data

In AHMbook: Functions and Data for the Book 'Applied Hierarchical Modeling in Ecology' Vols 1 and 2

Simulate non-hierarchical point transect (= point count) data

Description

Function simulates coordinates of individuals on a square with a count location at the center point.

Usage

sim.pdata(N = 1000, sigma = 1, B = 3, keep.all = FALSE, show.plot = TRUE)

Arguments

N	total population size in the square
sigma	scale of half-normal detection function
B	circle radius; the data are simulated over a square of side 2 * B, but individuals outside the circle of radius B are not detected.
keep.all	if TRUE, the data for all individuals are returned; if FALSE, only for individuals detected.
show.plot	choose whether to show plots or not. Set to FALSE when using function in simulations.

Value

A list with the following elements:

N	total population size in the square
sigma	scale of half-normal detection function
B	circle radius
u1, u2	the x and y coordinates of each of the individuals
d	the distance of each individual from the center of the circle
y	a 0/1 indicator showing whether each individual is detected or not, a vector of length N
N.real	the realized number of individuals within the circle of radius B

Author(s)

Marc Kéry & Andy Royle

References

Kéry, M. & Royle, J.A. (2016) Applied Hierarchical Modeling in Ecology AHM1 - 8.2.5.1.

Examples

# Simulate a data set with the default arguments and look at the structure of the output:
tmp <- sim.pdata()
str(tmp)

AHMbook documentation built on Sept. 12, 2024, 6:37 a.m.