Islope1 {DLMtool} | R Documentation |
A management procedure that incrementally adjusts the TAC to maintain a constant CPUE or relative abundance index.
Islope1(x, Data, reps = 100, plot = FALSE, yrsmth = 5, lambda = 0.4, xx = 0.2) Islope2(x, Data, reps = 100, plot = FALSE, yrsmth = 5, lambda = 0.4, xx = 0.3) Islope3(x, Data, reps = 100, plot = FALSE, yrsmth = 5, lambda = 0.4, xx = 0.4) Islope4(x, Data, reps = 100, plot = FALSE, yrsmth = 5, lambda = 0.2, xx = 0.4)
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 |
Years over which to calculate index |
lambda |
A gain parameter controlling the speed in update in TAC. |
xx |
Parameter controlling the fraction of mean catch to start using in first year |
The TAC is calculated as:
\textrm{TAC} = \textrm{TAC}^* ≤ft(1+λ I \right)
where \textrm{TAC}^* is 1-xx multiplied by the mean catch from the past yrsmth
years for the
first year and catch from the previous year in projection years,
λ is a gain parameter, and I is the slope of log index over the past yrsmth
years.
An object of class Rec-class
with the TAC
slot populated with a numeric vector of length reps
Islope1
: The least biologically precautionary of the Islope methods
Islope2
: More biologically precautionary. Reference TAC is 0.7 average catch
Islope3
: More biologically precautionary. Reference TAC is 0.6 average catch
Islope4
: The most biologically precautionary of the Islope methods.
Reference TAC is 0.6 average catch and gain parameter is 0.2
See Data-class
for information on the Data
object
Islope1
: Cat, Ind, LHYear, Year
See Online Documentation for correctly rendered equations
T. Carruthers
Carruthers et al. 2015. Performance evaluation of simple management procedures. ICES J. Mar Sci. 73, 464-482.
Geromont, H.F., Butterworth, D.S. 2014. Generic management procedures for data-poor fisheries; forecasting with few data. ICES J. Mar. Sci. doi:10.1093/icesjms/fst232
Other Index methods:
GB_slope()
,
GB_target()
,
Gcontrol()
,
ICI()
,
Iratio()
,
Itarget1_MPA()
,
Itarget1()
,
ItargetE1()
Islope1(1, MSEtool::SimulatedData, plot=TRUE) Islope2(1, MSEtool::SimulatedData, plot=TRUE) Islope3(1, MSEtool::SimulatedData, plot=TRUE) Islope4(1, MSEtool::SimulatedData, plot=TRUE)