Internal wrapper function to calculate MSY reference points (now using MSYCalcs)
optMSY_eq(x, yr.ind = 1, StockPars, V, Wt_age_C)
Results from MSYCalcs
Simulation number
Year index used in calculations
A list of stock parameters
Array of selectivity-at-age
Array of fishery weight at age. Optional. If missing, StockPars$Wt_age
is used.