Initial numbers and Beverton-Holt parameters

Computes the initial equilibrium numbers-at-age, unfished recruitment (R0), and Beverton-Holt stock-recruitment parameters.

Usage

get_initial_numbers(B0, steep, M_a, phi_ya)

Arguments

B0

Unfished spawning biomass.

steep

Beverton-Holt steepness parameter.

M_a

a vector of natural mortality at age.

phi_ya

a matrix by year of spawning output at age created using the get_phi function.

Value

A list containing:

Ninit

Initial numbers-at-age (vector).

R0

Unfished recruitment (scalar).

alpha

BH alpha parameter.

beta

BH beta parameter.