Generate Key Projection Quantities and Table Plot

Calculates biological and fishery reference points and performs population projections to estimate terminal spawning biomass, catch advice, and reference point values by model and region. Also returns a formatted table plot of key quantities.

Usage

get_key_quants(data, rep, reference_points_opt, proj_model_opt, model_names)

Arguments

data

A list of model input data objects, one for each model (i.e., a list of SPoRC-formatted data lists). Each element should contain information on regions, years, ages, fleets, and biological inputs (e.g., weight-at-age, maturity, mortality).

rep

A list of model output objects, one for each model (i.e., a list of SPoRC-formatted report lists). Each element must include recruitment, selectivity, mortality, and numbers-at-age.

reference_points_opt

A named list specifying options for reference point calculations. See Get_Reference_Points for more details. Must include:

SPR_x: Spawning potential ratio (e.g., 0.4) for calculating F reference points. May be NULL if using bh_rec.
t_spwn: Fraction of year when spawning occurs (e.g., 0.5).
sex_ratio_f: Proportion of recruits that are female.
calc_rec_st_yr: Start year for averaging recruitment.
rec_age: Recruitment age.
type: Reference point calculation method (e.g., "multi_region").
what: Type of output requested from the reference point function.

proj_model_opt

A named list of projection settings. See Do_Population_Projection for details. Must include:

n_proj_yrs: Number of years to project forward.
HCR_function: Harvest control rule function to use.
recruitment_opt: Recruitment assumption (e.g., "mean_rec", "bh_rec", "inv_gauss").
fmort_opt: Fishing mortality assumption (e.g., "input", "HCR").
n_avg_yrs: Number of years to average over for projection inputs.

model_names

A character vector of model identifiers (e.g., c("Base", "Alt1", "Alt2")), one for each element in data and rep.

Value

A list with two elements:

[[1]]: A data.frame of key quantities by model and region, including terminal SSB, catch advice, and reference points.
[[2]]: A cowplot table plot (ggdraw object) of the same key quantities.

Details

This function checks input list completeness, calculates reference points using Get_Reference_Points(), performs population projections with Do_Population_Projection(), and assembles both tabular and visual summaries.

If recruitment_opt is set to "inv_gauss", a warning is issued since only a single simulation will be run. This is typically not appropriate and an alternative assumption is recommended.

Examples

if (FALSE) { # \dontrun{
reference_points_opt <- list(SPR_x = 0.4,
                             t_spwn = 0,
                             sex_ratio_f = 0.5,
                             calc_rec_st_yr = 20,
                             rec_age = 2,
                             type = "multi_region",
                             what = "global_SPR")

proj_model_opt <- list(
  n_proj_yrs = 2,
  n_avg_yrs = 1,
  HCR_function = function(x, frp, brp, alpha = 0.05) {
    stock_status <- x / brp
    if (stock_status >= 1) f <- frp
    if (stock_status > alpha && stock_status < 1) f <- frp * (stock_status - alpha) / (1 - alpha)
    if (stock_status < alpha) f <- 0
    return(f)
  },
  recruitment_opt = "mean_rec",
  fmort_opt = "HCR"
)

out <- get_key_quants(list(mlt_rg_sable_data),
                      list(mlt_rg_sable_rep),
                      reference_points_opt,
                      proj_model_opt,
                      "Model 1")
out[[1]]  # key quantities data.frame
out[[2]]  # table plot
} # }