Perform a retrospective analysis, successive removals of most recent years of data to evaluate resulting parameter estimates.

## Usage

```
retrospective(x, ...)
# S4 method for Assessment
retrospective(x, nyr = 5, figure = TRUE)
# S4 method for RCModel
retrospective(x, nyr = 5, figure = TRUE)
```

## Arguments

- x
An S4 object of class Assessment or RCModel.

- ...
More arguments.

- nyr
The maximum number of years to remove for the retrospective analysis.

- figure
Indicates whether plots will be drawn.

## Value

A list with an array of model output and of model estimates from the retrospective analysis.

Figures showing the time series of biomass and exploitation and parameter estimates with successive number of years removed. For a variety of time series output (SSB, recruitment, etc.) and estimates (R0, steepness, etc.), also returns a matrix of Mohn's rho (Mohn 1999).

## References

Mohn, R. 1999. The retrospective problem in sequential population analysis: an investigation using cod fishery and simulated data. ICES Journal of Marine Science 56:473-488.

## Examples

```
# \donttest{
output <- SP(Data = swordfish)
get_retro <- retrospective(output, nyr = 5, figure = FALSE)
# }
```