Modifications to the Generalised Yield Model: updated input of recruitment time series data and annual fishing selectivity functions

Revisions to the Generalised Yield Model provide for re-estimating the recruitment series from survey data for each value of natural mortality used in the assessments, whenever it is altered over the range of uncertainty in M factored into the assessment process. Data from outputs from mixture analyses from surveys are input to the GYM in raw form. An example file is provided. Consequently, endeavouring to predetermine the recruitment series with an average value of M is no longer necessary for inputting to the GYM.
In addition, provision is now made for inputting different fishing selectivity functions for different years in the assessment model. This is done in the usual way but with repeated input sections for each year at which the selectivity is altered.