IT5 {DLMtool} | R Documentation |
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)
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. |
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 (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.
An object of class Rec-class
with the TAC
slot populated with a numeric vector of length reps
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
T. Carruthers
IT5(1, MSEtool::SimulatedData, plot=TRUE) IT10(1, MSEtool::SimulatedData, plot=TRUE)