extractMoves: Simulated Movements

In secr: Spatially Explicit Capture-Recapture

Simulated Movements

Description

Extract movements from a previously simulated multi-session population.

Usage

extractMoves(pop, plotn = NULL, add = FALSE, collapse = TRUE, maxradius = Inf, ...)

Arguments

pop	popn object from sim.popn
plotn	integer maximum number of instances to plot at each session
add	logical for whether to add to existing plot
collapse	logical; if TRUE plots for sessions 2, 3,... are added to the first
maxradius	numeric radius for selecting subset of initial locations
...	arguments passed to arrows

Details

This function is mostly used to check the movement simulations.

Moves are constrained by the edge (argument ‘edgemethod’ of sim.popn). ‘maxradius’ may be set to restrict the extraction to the subset of animals initially near the centroid of the arena in each session.

Plotting uses the graphics function arrows that has some quirks, such as difficult-to-suppress warnings for zero-length moves. Set code = 0 to suppress arrowheads; length = 0.1 to shorten to 0.1 inches, etc.

Value

List of data frames, one for each session but the last (columns ‘x1’,‘y1’,‘x2’,‘y2’,‘d’).

See Also

turnover, sim.popn

Examples

set.seed(12345)
pop3 <- sim.popn(D = 2, core = make.grid(), buffer = 200, nsessions = 3, 
    details = list(lambda = 1.0, movemodel = 'BVE', move.a = 50, 
    edgemethod = 'stop'))
m <- extractMoves(pop3, plotn = 10, length = 0.1)
mean(unlist(sapply(m, '[', 'd')))    # less than nominal 2 x move.a

# For distances closer to nominal for BVE (2 x move.a = 100), 
# increase size of arena (e.g., buffer = 500) and consider only 
# central animals (e.g., maxradius = 300).

secr documentation built on Oct. 18, 2023, 1:07 a.m.