growth_soVB2: seasonally oscillating von Bertalanffy growth function (using...

In marchtaylor/fishdynr: Fisheries science related population dynamics models

Description

growth_soVB2 describes the growth as a function of age (t) using the seasonally oscillating von Bertalanffy growth function (Somers 1988). The function differs slightly from growth_soVB by using L0 instead of t0 to describe the growth function origin.

Usage

growth_soVB2(Linf, K, t, L0, ts, C)

Arguments

Linf	Infinite length
K	growth constant
t	age
L0	(hypothetical) length at time zero
ts	summer point. Time of year (between 0 and 1) when growth oscillation cycle begins (sine wave term becomes positive). Note that this definition differs from some interpretations of the model (see Somers 1998)
C	oscillation strength. Varies between 0 and 1.

Examples

t <- seq(0,5,0.1)
L <- growth_soVB2(Linf=100, K=0.5, t=t, L0=10, ts=0.5, C=0.5)
plot(t, L, t="l", ylim=c(0,110), xaxs="i", yaxs="i")
points(0,10); abline(h=100, lty=2, col=8)

marchtaylor/fishdynr documentation built on May 21, 2019, 11:27 a.m.