SPmod {DLMtool} | R Documentation |
An MP that makes incremental adjustments to TAC recommendations based on the apparent trend in surplus production. Based on the theory of Mark Maunder (IATTC)
SPmod(x, Data, reps = 100, plot = FALSE, alp = c(0.8, 1.2), bet = c(0.8, 1.2))
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? |
alp |
Condition for modifying the TAC (bounds on change in abundance) |
bet |
Limits for how much the TAC can change among years |
Note that this isn't exactly what Mark has previously suggested and is stochastic in this implementation.
The TAC is calculated as:
where \textrm{bet}_1 and \textrm{bet}_2 are elements in bet
,
r is the ratio of the index in the most recent two years, C_{y-1}
is catch in the previous year, b_1 and b_2 are ratio of index
in y-2 and y-1 over the estimate of catchability ≤ft(\frac{I}{A}\right),
and α_1, α_2, and α_3 are specified in argument
alp
.
An object of class Rec-class
with the TAC
slot populated with a numeric vector of length reps
A numeric vector of TAC recommendations
See Data-class
for information on the Data
object
SPmod
: Cat, Ind
See Online Documentation for correctly rendered equations
T. Carruthers
http://www.iattc.org/Meetings/Meetings2014/MAYSAC/PDFs/SAC-05-10b-Management-Strategy-Evaluation.pdf
Other Surplus production MPs:
Fadapt()
,
Rcontrol()
,
SPMSY()
,
SPSRA()
,
SPslope()
SPmod(1, Data=MSEtool::Atlantic_mackerel, plot=TRUE)