Tune daily costs so that a target fleet composition is an open-access equilibrium

At open access each segment's active days are the share of its vessels that break even (heterogeneous vessel efficiency), so the composition of the active fleet is set by the daily costs. The G log cost multipliers are solved so that G residuals vanish: the shares of days of the first G - 1 segments and one status target for the stocks, r = (log share_g / target_g, g < G; log status / target). Newton steps with a forward-difference Jacobian; the base point and the G perturbed points run in one vectorised call (warm-started).

Usage

ms_tune(
  sys,
  shares = sys$segments,
  status = c(median = 0.9),
  cap = 1000,
  max_iter = 25,
  tol = 0.02,
  h = 0.05,
  max_step = 0.5,
  years_first = 400,
  years = 250,
  avg_years = 30,
  verbose = TRUE,
  ...
)

Arguments

sys

an ms_system.

shares

target share of active days by segment (default the share_target of the segment table)

status

c(median = x): median B/Bmsy; c(min = x): the weakest stock; c(E_total = x): total active days

cap

fleet capacity (registered days) by segment

max_iter, tol, h, max_step

Newton settings.

years_first, years, avg_years

years of the first and later runs, and years averaged.

verbose

print progress.

...

passed to ms_simulate() (gamma, ...)

Value

the tuned system (cost_seg replaced), with attributes "tuning" (history), "status_quo" (the open-access equilibrium) and "converged"