Harvest rate calculation

Computes age-specific harvest rates by fishery for a single year-season combination, using the Baranov catch equation.

Usage

get_harvest_rate(data, y, s, number_ysa, sel_fya, weight_fya)

Arguments

data

A list of model data. Must contain: n_fishery, n_age, catch_obs_ysf, catch_units_f.

y

Integer. Year index (1-based).

s

Integer. Season index (1-based).

number_ysa

Numeric array [n_year+1, n_season, n_age]. Current numbers-at-age.

sel_fya

Numeric array [n_fishery, n_year, n_age]. Selectivity at age by fishery and year.

weight_fya

Numeric array [n_fishery, n_year, n_age]. Mean weight at age by fishery and year. Passed explicitly so AD gradients propagate if growth is ever estimated.

Value

A named list with:

h_rate_fa

Harvest rate array [n_fishery, n_age].

h_rate_a

Total harvest rate vector (length n_age).

penalty

Penalty from posfun for harvest-rate constraint.

Details

weight_fya is passed as an explicit argument (not read from data) so that AD gradients propagate correctly if growth parameters are estimated in the future.