getMSY: getMSY calculates the MSY for the Polacheck et al 1993...

In MQMF: Modelling and Quantitative Methods in Fisheries

getMSY calculates the MSY for the Polacheck et al 1993 equation

Description

getMSY calculates the MSY for the Polacheck et al 1993 generalized surplus production equation. This simplifies to rK/4 when p = 1.0. But this is a general equation that covers off for all positive values of p.

Usage

getMSY(pars, p = 1)

Arguments

pars	the model parameters r, K, Binit, sigma; p is kept separate
p	asymmetry parameter for the Polacheck et al 1993 equation, default=1.0 = Schaefer

Value

the MSY

References

Polacheck, T., Hilborn, R., and A.E. Punt (1993) Fitting surplus production models: Comparing methods and measuring uncertainty. Canadian Journal of Fisheries and Aquatic Sciences, 50: 2597-2607.

Examples

param <- c(r=1.1,K=1000.0,Binit=800.0,sigma=0.075)
getMSY(param,p=1.0)     #  275       Schaefer equivalent
getMSY(param,p=1e-08)   #  404.6674  Fox equivalent

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