Buffer Harvest Control Rule (HCR) — buffer.hcr • msemodules

Implements a "buffer" style harvest control rule (HCR) using a metric (e.g., mean index or biomass) compared against defined buffer and limit reference points, with soft- and hard-caps and optional bounds on TAC changes.

buffer.hcr(
  stk,
  ind,
  metric = "wmean",
  target = 1,
  width = 0.5,
  lim = max(target * 0.1, target - 2 * width),
  bufflow = max(lim * 1.5, target - width),
  buffupp = target + width,
  sloperatio = 0.15,
  initial,
  nyears = 4,
  dupp = NULL,
  dlow = NULL,
  all = TRUE,
  ...,
  args,
  tracking
)

plot_buffer.hcr(
  args,
  obs = "missing",
  alpha = 0.3,
  labels = c(lim = "limit", bufflow = "Lower~buffer", buffupp = "Upper~buffer", metric =
    metric, output = output),
  metric = args$metric,
  output = "multiplier",
  xlim = buffupp * 1.5,
  ylim = scale * 1.5
)

Arguments

stk: The 'oem' observation or SA estimation, an FLStock object.
ind: Possible indicators returned by the 'est' step, FLQuants.
metric: The metric name used for the x-axis label.
target: The desired target value for the metric, defaults to 1. Numeric or FLQuant.
width: Numeric. The width of the buffer zone surrounding the target. Default is 0.5.
lim: Numeric. The lower threshold beyond which the HCR steeply reduces catch. Default is max(target * 0.10, target - 2 * width).
bufflow: Numeric. The lower bound of the buffer range. Default is max(lim * 1.50, target - width).
buffupp: Numeric. The upper bound of the buffer range. Default is target + width.
sloperatio: Numeric. Defines the slope for values exceeding the buffer's upper limit. Default is 0.15.
initial: Numeric or FLQuant. The previous year's TAC value or another scaling factor for outputs.
nyears: Numeric. Number of years to use for windowing or smoothing metrics. Default is 4.
dupp: A limit for the increase in the output variable, e.g. 1.15 for a maximum increase of 15%, numeric. No limit is applied if NULL.
dlow: A limit for the decrease in the output variable, e.g. 0.85 for a maximum decrease of 15%, numeric. No limit is applied if NULL.
all: If TRUE, upper and lower limits (dupp and dlow) are applied unconditionally, otherwise only when metric > trigger, logical.
...: Any extra arguments to be passed to the function computing 'metric'.
args: list. The list of parameters used by the buffer.hcr function.
tracking: An FLQuant used for tracking indicators, intermediate values, and decisions during MP evaluation.
obs: Observed values to overlay on the plot.
alpha: Alpha transparency for observed points/lines.
labels: Labels for the plot annotations. A list with names among 'lim', 'bufflow', 'buffupp', 'metric', and 'output'.
output: The output name used for the y-axis label.
xlim: The maximum x-axis limit for the plot.
ylim: The maximum y-axis limit for the plot.

Value

ggplot2 object

Details

plot_buffer.hcr Plots the buffer harvest control rule (HCR) curve along with optional observed values.