optistock (version 0.0.2)

total_cost: Compute direct total cost to raise hatchery fish

Description

This function computes the total cost to raise fish in a hatchery until time. This function differs from total_daily_cost by directly computing the total cost rather than integrating a daily cost estimate.

Usage

total_cost(
  time,
  time_slope = 1,
  time_exp = 1,
  init_cost = 0,
  recruits = 1,
  rec_exp = 1
)

Value

A vector of values representing cost for the given time, recruit number, and associated variables

Arguments

time

The amount of time that fish are raised in hatchery

time_slope

Controls how quickly the slope increases over time

time_exp

Controls the non-linearity of the curve over time

init_cost

The initial cost (i.e. intercept of the curve)

recruits

The number of recruits

rec_exp

Controls the non-linearity of the curve across recruit number

Details

The total_cost function computes a cost curve according to the following equation:

C = s_Tt^α * s₂R^β + b

where α corresponds to the time_slope argument, γ is the time_exp parameter, β is the intercept (or init_cost), R is the number of recruits, and τ is the recruitment exponent corresponding to rec_exp

Examples

curve(total_cost(x, time_slope = 0.05, time_exp = 1.2), 0, 100)
curve(total_cost(x, time_slope = 0.05, time_exp = 0.5), 0, 100)