fitness_func: Fitness functions

In TheoPannetier/comrad: R implementation of a Competitive Radiation model

Fitness functions

Description

A set of equations to compute the fitness of an individual. All three functions specify a decline of fitness with local niche saturation, but the starting and saturation fitness differ (see Details).

Usage

fitness_func_logistic(growth_rate, n_eff, carrying_cap)

fitness_func_pontarp(growth_rate, n_eff, carrying_cap)

fitness_func_ricker(growth_rate, n_eff, carrying_cap)

Arguments

growth_rate	numeric ⁠>= 0⁠, the baseline growth rate. Generations being discrete, high values will cause chaos.
n_eff	Effective population size experienced by an individual, see get_n_eff()
carrying_cap	The carrying capacity experienced by an individual, see get_carrying_cap().

Details

The table below reports the fitness values associated with hallmark levels of saturation. Note that all three functions are pmax()'d.

Neff / K	0	1/2	1	2	infty
logistic	r	r/2	0	0	0
pontarp	1 + r	1 + r/2	1	1 - r	0
ricker	exp(r)	exp(r/2)	1	exp(-r)	0

Author(s)

Théo Pannetier

TheoPannetier/comrad documentation built on April 8, 2023, 8:06 a.m.