`Gcontrol.Rd`

A harvest control rule proposed by Carl Walters that uses trajectory in inferred surplus production to make upward/downward adjustments to TAC recommendations

```
Gcontrol(
x,
Data,
reps = 100,
plot = FALSE,
yrsmth = 10,
gg = 2,
glim = c(0.5, 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?

- yrsmth
The number of years over which to smooth catch and biomass data

- gg
A gain parameter

- glim
A constraint limiting the maximum level of change in quota recommendations

An object of class `Rec-class`

with the `TAC`

slot populated with a numeric vector of length `reps`

The TAC is calculated as:
$$\textrm{TAC} = \textrm{SP} \left(1-gG\right)$$
where \(\textrm{SP}\) is the predicted surplus production for the next year,
*g* is a gain parameter, and *G* is the slope of surplus production
as a function of biomass over the last `yrsmth`

years.

The change in TAC is bounded by the `glim`

argument, which by default does not allow
the TAC to decrease by more than half or increase more than twice the last annual catch.

See Online Documentation for correctly rendered equations

Carruthers et al. 2015. Performance evaluation of simple management procedures. ICES J. Mar Sci. 73, 464-482.

```
Gcontrol(1, Data=MSEtool::Atlantic_mackerel, plot=TRUE)
#> TAC (median)
#> 6.529254
```