Internal function to calculate MSY Reference Points
MSYCalcs( logF, M_at_Age, Wt_at_Age, Mat_at_Age, Fec_at_Age, V_at_Age, maxage, R0x = 1, SRrelx = 3L, hx = 1, SSBpR = 0, opt = 1L, plusgroup = 1L )
log fishing mortality
Vector of M-at-age
Vector of weight-at-age
Vector of maturity-at-age
Vector of mature weight-at-age
Vector of selectivity-at-age
R0 for this simulation. Set = 1 if SRrelx = 3 for per-recruit calculations
SRR type for this simulation. Use 3 for per-recruit calculations, i.e. constant recruitment.
numeric. Steepness value for this simulation. Not used if SRrelx = 3.
numeric. Unfished spawners per recruit for this simulation. Not used if SRrelx = 3.
Option. 1 = return -Yield, 2= return all MSY calcs
Integer. Default = 0 = no plus-group. Use 1 to include a plus-group