IT5: Iterative Index Target MP

Description Usage Arguments Details Value Functions Required Data Rendered Equations Author(s) Examples

View source: R/MPs_Output.R

Description

An index target MP where the TAC is modified according to current index levels (mean index over last 5 years) relative to a target level.

Usage

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IT5(x, Data, reps = 100, plot = FALSE, yrsmth = 5, mc = 0.05)

IT10(x, Data, reps = 100, plot = FALSE, yrsmth = 5, mc = 0.1)

Arguments

x

A position in the data object

Data

A data object

reps

The number of stochastic samples of the MP recommendation(s)

plot

Logical. Show the plot?

yrsmth

The number of historical years over which to average the index

mc

The maximum fractional change in the TAC among years.

Details

The TAC is calculated as:

\textrm{TAC}_y = C_{y-1} I_δ

where C_{y-1} is the catch from the previous year and I_δ is the ratio of the mean index over the past yrsmth years to a reference index level. The maximum allowable change in TAC is determined by mc: e.g mc=0.05 means that the maximum change in TAC from the previous catch is 5%.

The reference index level ([email protected]) is assumed to be a proxy for MSY. In the MSE Iref is the index at MSY subject to observation error ([email protected]). Consequently the performance of these methods in MSE is strongly determined by the uncertainty the in reference index.

Value

An object of class Rec with the TAC slot populated with a numeric vector of length reps

Functions

Required Data

See Data for information on the Data object

IT5: Ind, Iref, MPrec

IT10: Ind, Iref, MPrec

Rendered Equations

See Online Documentation for correctly rendered equations

Author(s)

T. Carruthers

Examples

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DLMtool documentation built on March 13, 2020, 2:52 a.m.