IT5.Rd
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.
IT5(x, Data, reps = 100, plot = FALSE, yrsmth = 5, mc = 0.05)
IT10(x, Data, reps = 100, plot = FALSE, yrsmth = 5, mc = 0.1)
A position in the data object
A data object
The number of stochastic samples of the MP recommendation(s)
Logical. Show the plot?
The number of historical years over which to average the index
The maximum fractional change in the TAC among years.
An object of class Rec-class
with the TAC
slot populated with a numeric vector of length reps
The TAC is calculated as:
$$\textrm{TAC}_y = C_{y-1} I_\delta$$
where \(C_{y-1}\) is the catch from the previous year and \(I_\delta\) 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 (Data@Iref
) is assumed to be a proxy for MSY. In the
MSE Iref
is the index at MSY subject to observation error (Obs@Irefbiascv
).
Consequently the performance of these methods in MSE is strongly determined by the
uncertainty the in reference index.
IT5
: Maximum annual changes in TAC are 5 per cent.
IT10
: Maximum annual changes are 10 per cent.
See Data-class
for information on the Data
object
IT5
: Ind, Iref, MPrec
IT10
: Ind, Iref, MPrec
See Online Documentation for correctly rendered equations
IT5(1, MSEtool::SimulatedData, plot=TRUE)
#> TAC (median)
#> 1783.1
IT10(1, MSEtool::SimulatedData, plot=TRUE)
#> TAC (median)
#> 1824.35