recruit_funs: Basic functions for recruitment curves

In inspktrgadget/gadgetSim: Create Gadget replicates for use in simulation studies

Description

These functions produce the basic stock-recruitment curves used by Gadget. simple_ssb uses the equation μ * S, ricker returns the number of recruits per spawning stock biomass S per the Ricker formula:

R = μ S e^{-λ S}

. bev_holt returns the number of recruits using the Beverton-Holt recruitment curve

R = (μ * S)(λ + S)

Usage

simple_ssb(ssb, mu)

ricker(ssb, mu, lambda)

bev_holt(ssb, mu, lambda)

Arguments

ssb	Numeric. The spawning stock biomass used to compute the recruitment curve
mu	Numeric. Parameter that controls maximum number of recruits for bev_holt and ricker
lambda	Numeric. Controls density dependence in ricker curve and steepness in bev_holt

Value

A numeric vector the length of ssb

Examples

curve(ricker(x, 1000, 0.1), 0, 100, xlab = "SSB", ylab = "R")
curve(bev_holt(x, 3000, 10), add = TRUE, col = "red")

inspktrgadget/gadgetSim documentation built on May 10, 2019, 9:51 a.m.