* version 1.0.0  (STB-53: sg128)
program define nlvbgf
   version 6.0
      if "`1'"=="?"  {
         global S_2 /*
*/ "von Bertalanffy growth function,$S_E_depv=b0*(1-exp(-b1*(`2'-b2)))"
         global S_1 "b0 b1 b2"
         local exp "[$S_E_wgt $S_E_exp]"
         global b0=500
         global b1=1
         global b2=0.1
         exit
      }
      replace `1'= $b0*(1-exp(-$b1*(`2'-$b2)))
end