projection: Projections for assessment models

In SAMtool: Stock Assessment Methods Toolkit

Projections for assessment models

Description

This function takes an assessment model and runs a stochastic projection based on future F or catch.

Usage

projection(
  Assessment,
  constrain = c("F", "Catch"),
  Ftarget,
  Catch,
  p_years = 50,
  p_sim = 200,
  obs_error,
  process_error,
  max_F = 3,
  seed = 499
)

Arguments

Assessment	An object of class Assessment.
constrain	Whether to project on future F or catch. By default, projects on F.
Ftarget	The projection F, either of length 1 for constant F for the entirety of the projection or length p_years.
Catch	The projection catch, either of length 1 for constant catch for the entirety of the projection or length p_years.
p_years	Integer for the number of projection years.
p_sim	Integer for the number of simulations for the projection.
obs_error	A list of length two. In the first entry, a vector of length nsurvey giving the standard deviations of each future index, or alternatively an array of dimension p_sim, p_years, and nsurvey giving the deviates. The second entry is the standard deviation of the projected catch. Alternatively, a matrix of simulation and year-specific error structure for the catch (p_sim rows and p_year columns; a matrix of ones indicates perfect data).
process_error	Numeric, standard deviation for process error (e.g., recruitment or biomass deviates). If NULL, uses values from assessment model. Alternatively, a matrix of simulation and year-specific recruitment deviates (p_sim rows and p_year columns, a matrix of ones indicates no recruitment deviates).
max_F	The maximum allowable F if the projection is constrained on catch.
seed	An integer to set the seed for the sampling observation and process error deviates.

Value

An object of class project that contains future predicted values of F, catch, biomass, recruitment, etc.

Examples

myAssess <- SP(Data = swordfish)
do_projection <- projection(myAssess, Ftarget = myAssess@FMSY)

SAMtool documentation built on Sept. 11, 2024, 8:07 p.m.