Generate linear or negative exponential dispersal kernel functions, taking a distance, d, and returning the probability density of dispersing that distance.

dispersal_linear(dmax)

dispersal_negexp(alpha)

Arguments

dmax

numeric; maximum dispersal distance.

alpha

numeric; exponential decay rate parameter, equal to the inverse of the mean dispersal distance.

Value

A dispersal kernel function.

Details

The available dispersal kernel functions are:

  • dispersal_linear: decays linearly from 1 and d = 0 to 0 at d = dmax.

  • dispersal_negexp: decays exponentially with rate parameter alpha.

Examples

dl <- dispersal_linear(10) dne <- dispersal_negexp(1/5) dl(5)
#> [1] 0.5
dne(5)
#> [1] 0.3678794