fabens: fabens calculates predicted growth increment for tagging data

In MQMF: Modelling and Quantitative Methods in Fisheries

fabens calculates predicted growth increment for tagging data

Description

fabens requires at least two parameters, Linf and K from the von Bertalanffy growth curve in a vector, as well as the initial length at the time of tagging and the change in time between tag release and recapture. It then calculates the expected growth increment.

Usage

fabens(par, indat, initL = "l1", delT = "dt")

Arguments

par	a vector of at least Linf, and K from the von Bertalanffy growth curve
indat	the matrix or data.frame of data columns containing at least the initial lengths at atgging and the deltaT, time intervals between tag release and recapture.
initL	column name of the initial lengths within indat, default="l1"
delT	column name of the time interval, deltaT, within indat, default="dt"

Value

a vector of predicted growth increments

Examples

 data(blackisland)
 oldpar <- par(no.readonly=TRUE)
 plot(blackisland$l1,blackisland$dl,type="p",pch=16,
 xlab="Initial Length mm",ylab="Growth Increment mm",
 panel.first=grid())
 abline(h=0)
 param <- c(170, 0.3, 4.0) # Linf, K, sigma
 predDL <- fabens(param,blackisland,initL="l1",delT="dt")
 lines(blackisland$l1,predDL,col=2,lwd=2)  
 par(oldpar) 

MQMF documentation built on Sept. 8, 2023, 5:14 p.m.