hconv {MSEtool}

Stock recruit parameterization

Description

Convert stock recruit parameters from steepness parameterization to alpha/beta (and vice versa)

Usage

hconv(alpha, phi0, SR = 1, type = 1)

R0conv(alpha, beta, phi0, SR = 1, type = 1)

SRalphaconv(h, phi0, SR = 1, type = 1)

SRbetaconv(h, R0, phi0, SR = 1, type = 1)

Arguments

alpha

Alpha parameter

phi0

Unfished spawners per recruit

SR

Stock-recruit function: (1) Beverton-Holt, or (2) Ricker

type

The parameterization of the Beverton-Holt function with respect to alpha and beta. See details.

beta

Beta parameter

h

Steepness parameter

R0

Unfished recruitment parameter

Details

The Type 1 Beverton-Holt equation is

R = \alpha S/(1 + \beta S)

The Type 2 Beverton-Holt equation is

R = S/(\alpha + \beta S)

The Ricker equation is

R = \alpha S \exp(-\beta S)

Value

A numeric.

Functions

• hconv(): Returns steepness (h) from alpha and phi0

• R0conv(): Returns unfished recruitment (R0) from alpha, beta, and phi0

• SRalphaconv(): Returns alpha from h and phi0

• SRbetaconv(): Returns beta from h, R0, and phi0

Author(s)

Q. Huynh