Calculate Initial Numbers-at-Age (Version 1)

Usage

get_initial_numbers_v1(B0, steep, M_a, phi_ya)

Arguments

B0: A numeric scalar, unfished spawning biomass.
steep: A numeric scalar, steepness parameter for Beverton-Holt stock-recruitment.
M_a: A numeric vector of length n_age, natural mortality-at-age.
phi_ya: A numeric matrix of dimensions \[n_year + 1, n_age\], reproductive output-at-age.

Value

A list containing:

Ninit: Initial numbers-at-age (numeric vector)
R0: Unfished recruitment (numeric scalar)
alpha: Beverton-Holt alpha parameter (numeric scalar)
beta: Beverton-Holt beta parameter (numeric scalar)

Legacy status

These functions reproduce historical version-1 assessment code for audit and comparison. They are not the production SBT objective, do not implement the current data, mortality, harvest-wall, or biological-state contracts, and receive only compatibility maintenance. New analyses should use get_data(), sbt_model(), and the current component helpers.